Ports: each node checks the others' ports from outside

Phase 2e of the DLP and mail flow rules spec, the API half.

- inbuxa:MailRule/get and /set under urn:inbuxa:jmap. Rules convert
  through serde, so what a client sends is the stored format. A create
  or change is validated whole (Rule::validate) and refused with the
  property at fault; id, createdBy, createdAt and updatedAt are the
  server's. Every change goes through the request layer's audit record.
- Six permissions, ids 674-679 (enum and schema labels): mail flow rules
  (sysMailRuleGet/Update), DLP rules (sysDlpPolicyGet/Update) and held
  mail (sysDlpReviewGet/Update, for phase 3). Either kind's permission
  gets through the gate; the handler shows and changes each rule only
  with its own kind's. All server-level: a tenant is refused (settled
  answer 3).
- Administrators get all six; the server-level Compliance Officer gets
  DLP rules to see and held mail to review (settled answer 4), added
  once to an existing server's officer role by the grant mechanism,
  which gains an officer audience.
- Privacy catalog entry for inbuxa:MailRule.

tests/src/system/mail_rules.rs: create, list in order, validation,
server-set properties refused, update, kind-separated permissions for
an officer, destroy, audit records.

Cargo.lock

@@ -3947,9 +3947,12 @@ name = "inbuxa-features"
 version = "0.16.22"
 dependencies = [
  "ahash",
+ "aho-corasick",
  "base64 0.23.1",
  "flate2",
  "jmap_proto",
+ "quick-xml 0.41.0",
+ "regex",
  "registry",
  "serde",
  "serde_json",
@@ -3961,6 +3964,7 @@ dependencies = [
  "types",
  "utils",
  "xxhash-rust",
+ "zip",
 ]
 
 [[package]]

crates/common/src/auth/permissions.rs

@@ -296,6 +296,17 @@ impl Default for DefaultPermissions {
                     default.superuser.push(permission);
                     default.tenant.push(permission);
                 }
+                // inbuxa: DLP and mail flow rules, and held mail, are the
+                // server's: never a tenant's (dlp-and-mail-flow-rules spec,
+                // settled answer 3)
+                Permission::SysMailRuleGet
+                | Permission::SysMailRuleUpdate
+                | Permission::SysDlpPolicyGet
+                | Permission::SysDlpPolicyUpdate
+                | Permission::SysDlpReviewGet
+                | Permission::SysDlpReviewUpdate => {
+                    default.superuser.push(permission);
+                }
                 // inbuxa: AL-12: tenant administrators lock and delegate
                 // within their tenant
                 Permission::SysAccountLockGet

crates/common/src/manager/compliance_roles.rs

@@ -65,6 +65,10 @@ const OFFICER: &[Permission] = &[
     Permission::SysLegalHoldUpdate,
     Permission::SysLegalHoldExport,
     Permission::SysAccountLockGet,
+    // dlp-and-mail-flow-rules spec, §2.8: see DLP rules, review held mail
+    Permission::SysDlpPolicyGet,
+    Permission::SysDlpReviewGet,
+    Permission::SysDlpReviewUpdate,
 ];
 
 /// What a tenant's officer holds besides [`READS`].
@@ -113,6 +117,11 @@ fn created_key(tenant: Option<Id>) -> ValueClass {
     })
 }
 
+/// The server-level Compliance Officer role the server made, if it has.
+pub async fn server_role(data: &Store) -> trc::Result<Option<Id>> {
+    recorded(data, None).await
+}
+
 async fn recorded(data: &Store, tenant: Option<Id>) -> trc::Result<Option<Id>> {
     Ok(data
         .get_value::<u64>(ValueKey::from(created_key(tenant)))
@@ -172,13 +181,19 @@ pub async fn ensure_compliance_roles(registry: &RegistryStore, data: &Store) ->
 
 /// A new tenant gets its Compliance Officer role.
 pub async fn tenant_created(registry: &RegistryStore, data: &Store, tenant: Id) -> trc::Result<()> {
-    create_once(registry, data, Some(tenant), tenant_role(tenant)).await.map(|_| ())
+    create_once(registry, data, Some(tenant), tenant_role(tenant))
+        .await
+        .map(|_| ())
 }
 
 /// Before a tenant is deleted: removes its Compliance Officer role if nobody
 /// holds it, so the role doesn't block the delete. Returns whether it did,
 /// so a delete refused for another reason can put it back.
-pub async fn tenant_deleting(registry: &RegistryStore, data: &Store, tenant: Id) -> trc::Result<bool> {
+pub async fn tenant_deleting(
+    registry: &RegistryStore,
+    data: &Store,
+    tenant: Id,
+) -> trc::Result<bool> {
     let Some(role) = recorded(data, Some(tenant)).await? else {
         return Ok(false);
     };
@@ -220,7 +235,9 @@ mod tests {
             // Beyond what any user holds for their own account
             for permission in all.into_iter().filter(|p| !user.contains(p)) {
                 let name = permission.as_str();
-                let holds = name.starts_with("sysLegalHold");
+                // Placing holds and reviewing held mail are the officer's
+                // job, not settings (settled answers 2 and 4)
+                let holds = name.starts_with("sysLegalHold") || name.starts_with("sysDlpReview");
                 assert!(
                     !(name.ends_with("Update") && !holds)
                         && !(name.ends_with("Create") && !holds)
@@ -249,7 +266,11 @@ mod tests {
             assert!(officer.contains(&hold));
             assert!(!tenant.contains(&hold));
         }
-        for both in [Permission::SysComplianceGet, Permission::SysAuditGet, Permission::SysAccountGet] {
+        for both in [
+            Permission::SysComplianceGet,
+            Permission::SysAuditGet,
+            Permission::SysAccountGet,
+        ] {
             assert!(officer.contains(&both) && tenant.contains(&both));
         }
         assert!(!officer.contains(&Permission::SysAuditSettingsUpdate));
@@ -257,9 +278,15 @@ mod tests {
 
     #[test]
     fn records_are_per_place() {
-        let ValueClass::Any(server) = created_key(None) else { panic!() };
-        let ValueClass::Any(a) = created_key(Some(Id::from(1u64))) else { panic!() };
-        let ValueClass::Any(b) = created_key(Some(Id::from(2u64))) else { panic!() };
+        let ValueClass::Any(server) = created_key(None) else {
+            panic!()
+        };
+        let ValueClass::Any(a) = created_key(Some(Id::from(1u64))) else {
+            panic!()
+        };
+        let ValueClass::Any(b) = created_key(Some(Id::from(2u64))) else {
+            panic!()
+        };
         assert_eq!(server.key, b"Pc");
         assert_ne!(a.key, b.key);
         assert!(a.key.starts_with(b"Pc"));

crates/common/src/manager/granted_permissions.rs

@@ -46,6 +46,21 @@ const ADMIN_GRANTS: &[Permission] = &[
     Permission::SysLegalHoldUpdate,
     Permission::SysLegalHoldExport,
     Permission::SysComplianceGet,
+    Permission::SysMailRuleGet,
+    Permission::SysMailRuleUpdate,
+    Permission::SysDlpPolicyGet,
+    Permission::SysDlpPolicyUpdate,
+    Permission::SysDlpReviewGet,
+    Permission::SysDlpReviewUpdate,
+];
+
+/// Granted to the server-level Compliance Officer role once it exists:
+/// seeing DLP rules and reviewing held mail (dlp-and-mail-flow-rules spec,
+/// §2.8, settled answer 4). A new install's role has them from the start.
+const OFFICER_GRANTS: &[Permission] = &[
+    Permission::SysDlpPolicyGet,
+    Permission::SysDlpReviewGet,
+    Permission::SysDlpReviewUpdate,
 ];
 
 /// Granted to the default tenant administrator roles: reading and exporting
@@ -65,13 +80,16 @@ const TENANT_GRANTS: &[Permission] = &[
 enum Audience {
     Admin,
     Tenant,
+    Officer,
 }
 
 fn granted_key(permission: Permission, audience: Audience) -> ValueClass {
     let mut key = b"Pg".to_vec();
     // Admin grants keep the key they were first recorded under
-    if audience == Audience::Tenant {
-        key.extend_from_slice(b"tenant:");
+    match audience {
+        Audience::Admin => {}
+        Audience::Tenant => key.extend_from_slice(b"tenant:"),
+        Audience::Officer => key.extend_from_slice(b"officer:"),
     }
     key.extend_from_slice(permission.as_str().as_bytes());
     ValueClass::Any(AnyClass {
@@ -82,7 +100,8 @@ fn granted_key(permission: Permission, audience: Audience) -> ValueClass {
 
 pub(crate) async fn grant_new_admin_permissions(bp: &mut Bootstrap) -> trc::Result<()> {
     grant(bp, Audience::Admin, ADMIN_GRANTS).await?;
-    grant(bp, Audience::Tenant, TENANT_GRANTS).await
+    grant(bp, Audience::Tenant, TENANT_GRANTS).await?;
+    grant(bp, Audience::Officer, OFFICER_GRANTS).await
 }
 
 async fn grant(bp: &mut Bootstrap, audience: Audience, grants: &[Permission]) -> trc::Result<()> {
@@ -101,10 +120,17 @@ async fn grant(bp: &mut Bootstrap, audience: Audience, grants: &[Permission]) ->
     if pending.is_empty() {
         return Ok(());
     }
+    // The officer role is the one the server made, if it has made it yet: a
+    // new install makes it after this, with the permissions already in it
+    let admin_roles: Vec<Id> = if audience == Audience::Officer {
+        super::compliance_roles::server_role(&bp.data_store)
+            .await?
+            .into_iter()
+            .collect()
+    } else {
         // An administrator's default roles include the plain User role, which
         // every user also holds; only roles that are the audience's alone get it
-    let admin_roles: Vec<Id> = bp
-        .registry
+        bp.registry
             .object::<Authentication>(Id::singleton())
             .await?
             .map(|auth| {
@@ -118,7 +144,7 @@ async fn grant(bp: &mut Bootstrap, audience: Audience, grants: &[Permission]) ->
                         ]
                         .concat(),
                     ),
-                Audience::Tenant => (
+                    Audience::Tenant | Audience::Officer => (
                         auth.default_tenant_role_ids.as_slice(),
                         [
                             auth.default_user_role_ids.as_slice(),
@@ -133,7 +159,8 @@ async fn grant(bp: &mut Bootstrap, audience: Audience, grants: &[Permission]) ->
                     .copied()
                     .collect()
             })
-        .unwrap_or_default();
+            .unwrap_or_default()
+    };
     // Fetched by id: the registry's listing doesn't reach stored roles
     for role_id in admin_roles {
         let Some(stored) = bp

crates/features/Cargo.toml

@@ -21,6 +21,11 @@ base64 = "0.23"
 sha2 = "0.11"
 flate2 = "1.1"
 tokio = { version = "1.53", features = ["sync", "rt"] }
+# inbuxa: DLP detectors and attachment text (dlp-and-mail-flow-rules spec)
+regex = "1.13.1"
+aho-corasick = "1.1"
+zip = "8.6"
+quick-xml = "0.41"
 
 [dev-dependencies]
 tokio = { version = "1.53", features = ["macros", "rt"] }

crates/features/src/lib.rs

@@ -23,6 +23,7 @@ pub mod audit;
 pub mod branding;
 pub mod hold;
 pub mod lock;
+pub mod mailflow;
 pub mod masked_email;
 pub mod privacy;
 pub mod security;

crates/features/src/mailflow/cache.rs

@@ -0,0 +1,53 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! The compiled rules, kept per node so a message doesn't read the store.
+//! A change made on this node applies at once; one made on another node
+//! within [`TTL`], when the copy here is next refreshed.
+
+use super::{engine::Compiled, rules};
+use std::{
+    sync::{Arc, RwLock},
+    time::{Duration, Instant},
+};
+use store::Store;
+
+/// How long a node keeps its copy before reading the rules again.
+pub const TTL: Duration = Duration::from_secs(30);
+
+static CACHE: RwLock<Option<(Instant, Arc<Compiled>)>> = RwLock::new(None);
+
+/// Forgets the copy, so the next message reads the rules again.
+pub fn invalidate() {
+    if let Ok(mut cache) = CACHE.write() {
+        *cache = None;
+    }
+}
+
+/// The enabled rules, compiled. A rule that no longer compiles is left out
+/// and reported, once per refresh.
+pub async fn compiled(data: &Store) -> trc::Result<Arc<Compiled>> {
+    if let Ok(cache) = CACHE.read()
+        && let Some((at, compiled)) = cache.as_ref()
+        && at.elapsed() < TTL
+    {
+        return Ok(compiled.clone());
+    }
+    let (compiled, skipped) = Compiled::new(&rules::all(data).await?);
+    for (id, reason) in skipped {
+        trc::event!(
+            Store(trc::StoreEvent::DataCorruption),
+            Id = u64::from(id),
+            Reason = reason,
+            Details = "Mail rule skipped: it no longer compiles"
+        );
+    }
+    let compiled = Arc::new(compiled);
+    if let Ok(mut cache) = CACHE.write() {
+        *cache = Some((Instant::now(), compiled.clone()));
+    }
+    Ok(compiled)
+}

crates/features/src/mailflow/detectors/africa.rs

@@ -0,0 +1,49 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! African identifiers (§2.3): South Africa's ID number.
+
+use super::{Detector, Findings, Region, Strength, checks, valid_short_date};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[Detector::new(
+    "za-id",
+    "South Africa: ID number",
+    Region::Africa,
+    Strength::Checked,
+    za_id,
+)];
+
+/// Birth date `YYMMDD`, four digits, citizenship (0, 1 or 2), 8 or 9, a Luhn
+/// check digit. The date and the two fixed digits make it strong enough to
+/// count alone.
+static ZA_ID: LazyLock<Regex> = LazyLock::new(|| {
+    Regex::new(r"\b(\d{2})(\d{2})(\d{2})\d{4}[012][89]\d\b").expect("detector pattern")
+});
+
+fn za_id(text: &str, findings: &mut Findings) {
+    for c in ZA_ID.captures_iter(text) {
+        let n = &c[0];
+        let num = |s: &str| s.parse::<u32>().unwrap_or(0);
+        if valid_short_date(num(&c[1]), num(&c[2]), num(&c[3])) && checks::luhn(n) {
+            findings.insert(n);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    #[test]
+    fn south_africa() {
+        let detector = by_id("za-id").unwrap();
+        assert_eq!(detector.count("ID 8001015009087"), 1);
+        assert_eq!(detector.count("8001015009088"), 0);
+        assert_eq!(detector.count("8013015009087"), 0);
+    }
+}

crates/features/src/mailflow/detectors/americas.rs

@@ -0,0 +1,172 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Identifiers from the Americas outside the US and Canada (§2.3): Brazil's
+//! CPF and CNPJ, and Mexico's CURP.
+
+use super::{Detector, Findings, Region, Strength, digit_values, valid_short_date, word_near};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "br-cpf",
+        "Brazil: CPF",
+        Region::Americas,
+        Strength::Checked,
+        br_cpf,
+    ),
+    Detector::new(
+        "br-cnpj",
+        "Brazil: CNPJ",
+        Region::Americas,
+        Strength::Checked,
+        br_cnpj,
+    ),
+    Detector::new(
+        "mx-curp",
+        "Mexico: CURP",
+        Region::Americas,
+        Strength::Checked,
+        mx_curp,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+/// Brazil's mod 11 check digit over `digits` with `weights`.
+fn br_check(digits: &[u32], weights: &[u32]) -> u32 {
+    match digits.iter().zip(weights).map(|(a, w)| a * w).sum::<u32>() % 11 {
+        0 | 1 => 0,
+        r => 11 - r,
+    }
+}
+
+/// `111.444.777-35`, or eleven bare digits.
+static CPF: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d{3}(\.?)\d{3}(\.?)\d{3}(-?)\d{2}\b"));
+
+pub fn cpf_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    // A run of one digit passes the arithmetic but is never issued
+    d.len() == 11
+        && d.iter().any(|x| *x != d[0])
+        && br_check(&d[..9], &[10, 9, 8, 7, 6, 5, 4, 3, 2]) == d[9]
+        && br_check(&d[..10], &[11, 10, 9, 8, 7, 6, 5, 4, 3, 2]) == d[10]
+}
+
+const CPF_WORDS: &[&str] = &[
+    "cpf",
+    "cadastro de pessoas físicas",
+    "cadastro de pessoa física",
+];
+
+fn br_cpf(text: &str, findings: &mut Findings) {
+    for c in CPF.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let written = &c[1] == "." && &c[2] == "." && &c[3] == "-";
+        let n: String = whole
+            .as_str()
+            .chars()
+            .filter(char::is_ascii_digit)
+            .collect();
+        if cpf_valid(&n) && (written || word_near(text, whole.start(), whole.end(), CPF_WORDS)) {
+            findings.insert(n);
+        }
+    }
+}
+
+/// `11.222.333/0001-81`, or fourteen bare digits.
+static CNPJ: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b\d{2}(\.?)\d{3}(\.?)\d{3}(/?)\d{4}(-?)\d{2}\b"));
+
+pub fn cnpj_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    d.len() == 14
+        && d.iter().any(|x| *x != d[0])
+        && br_check(&d[..12], &[5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2]) == d[12]
+        && br_check(&d[..13], &[6, 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2]) == d[13]
+}
+
+const CNPJ_WORDS: &[&str] = &["cnpj", "cadastro nacional da pessoa jurídica"];
+
+fn br_cnpj(text: &str, findings: &mut Findings) {
+    for c in CNPJ.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let written = &c[1] == "." && &c[2] == "." && &c[3] == "/" && &c[4] == "-";
+        let n: String = whole
+            .as_str()
+            .chars()
+            .filter(char::is_ascii_digit)
+            .collect();
+        if cnpj_valid(&n) && (written || word_near(text, whole.start(), whole.end(), CNPJ_WORDS)) {
+            findings.insert(n);
+        }
+    }
+}
+
+/// Four letters, the birth date, sex (H, M or X), the state, three
+/// consonants, a character that tells the century apart, the check digit.
+static CURP: LazyLock<Regex> = LazyLock::new(|| {
+    re(r"(?i)\b[A-Z]{4}(\d{2})(\d{2})(\d{2})[HMX][A-Z]{2}[B-DF-HJ-NP-TV-Z]{3}[A-Z0-9]\d\b")
+});
+
+/// RENAPO's check: each character's place in `0-9 A-N Ñ O-Z`, weighted 18
+/// down to 2; the digit is 10 minus the sum mod 10 (10 becomes 0).
+pub fn curp_valid(curp: &str) -> bool {
+    const ALPHABET: &str = "0123456789ABCDEFGHIJKLMNÑOPQRSTUVWXYZ";
+    let mut sum = 0u32;
+    for (i, c) in curp.chars().take(17).enumerate() {
+        let Some(value) = ALPHABET.chars().position(|a| a == c) else {
+            return false;
+        };
+        sum += value as u32 * (18 - i as u32);
+    }
+    curp.chars().nth(17).and_then(|c| c.to_digit(10)) == Some((10 - sum % 10) % 10)
+}
+
+fn mx_curp(text: &str, findings: &mut Findings) {
+    for c in CURP.captures_iter(text) {
+        let curp = c[0].to_ascii_uppercase();
+        if valid_short_date(num(&c[1]), num(&c[2]), num(&c[3])) && curp_valid(&curp) {
+            findings.insert(curp);
+        }
+    }
+}
+
+fn num(s: &str) -> u32 {
+    s.parse().unwrap_or(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn brazil() {
+        assert_eq!(count("br-cpf", "CPF 111.444.777-35"), 1);
+        assert_eq!(count("br-cpf", "111.444.777-36"), 0);
+        assert_eq!(count("br-cpf", "pedido 11144477735"), 0);
+        assert_eq!(count("br-cpf", "cpf: 11144477735"), 1);
+        assert_eq!(count("br-cpf", "CPF 111.111.111-11"), 0);
+        assert_eq!(count("br-cnpj", "11.222.333/0001-81"), 1);
+        assert_eq!(count("br-cnpj", "11.222.333/0001-82"), 0);
+        assert_eq!(count("br-cnpj", "CNPJ 11222333000181"), 1);
+    }
+
+    #[test]
+    fn mexico() {
+        // python-stdnum's documented example
+        assert_eq!(count("mx-curp", "CURP BOXW310820HNERXN09"), 1);
+        assert_eq!(count("mx-curp", "BOXW310820HNERXN08"), 0);
+        assert_eq!(count("mx-curp", "BOXW311320HNERXN09"), 0);
+    }
+}

crates/features/src/mailflow/detectors/any.rs

@@ -0,0 +1,511 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Detectors that aren't tied to one country (§2.3, region "Any").
+
+use super::{
+    Detector, Findings, Region, Strength, checks, digits, stands_alone, valid_date, word_near,
+};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "payment-card",
+        "Payment card number",
+        Region::Any,
+        Strength::Checked,
+        payment_card,
+    ),
+    Detector::new("iban", "IBAN", Region::Any, Strength::Checked, iban),
+    Detector::new(
+        "swift-bic",
+        "SWIFT/BIC code",
+        Region::Any,
+        Strength::NeedsWord,
+        swift_bic,
+    ),
+    Detector::new(
+        "email-addresses",
+        "Email addresses",
+        Region::Any,
+        Strength::Checked,
+        email_addresses,
+    ),
+    Detector::new(
+        "phone-numbers",
+        "Phone numbers",
+        Region::Any,
+        Strength::NeedsWord,
+        phone_numbers,
+    ),
+    Detector::new(
+        "date-of-birth",
+        "Date of birth",
+        Region::Any,
+        Strength::NeedsWord,
+        date_of_birth,
+    ),
+    Detector::new(
+        "passport",
+        "Passport number",
+        Region::Any,
+        Strength::NeedsWord,
+        passport,
+    ),
+    Detector::new(
+        "private-key",
+        "Private key",
+        Region::Any,
+        Strength::Checked,
+        private_key,
+    ),
+    Detector::new(
+        "credentials",
+        "Cloud and service credentials",
+        Region::Any,
+        Strength::Checked,
+        credentials,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+// --- Payment cards --------------------------------------------------------
+
+/// Issuer prefixes (ISO/IEC 7812 IINs) and the lengths each network issues.
+fn card_network(number: &str) -> bool {
+    let len = number.len();
+    let prefix = |n: usize| number[..n].parse::<u32>().unwrap_or(0);
+    match number.as_bytes()[0] {
+        // Visa
+        b'4' => matches!(len, 13 | 16 | 19),
+        b'5' => {
+            // Mastercard 51–55; Maestro 50, 56–58
+            (51..=55).contains(&prefix(2)) && len == 16
+                || matches!(prefix(2), 50 | 56..=58) && (12..=19).contains(&len)
+        }
+        // Mastercard 2221–2720
+        b'2' => (2221..=2720).contains(&prefix(4)) && len == 16,
+        b'3' => {
+            // American Express 34, 37; JCB 3528–3589; Diners 300–305, 36, 38, 39
+            matches!(prefix(2), 34 | 37) && len == 15
+                || (3528..=3589).contains(&prefix(4)) && (16..=19).contains(&len)
+                || ((300..=305).contains(&prefix(3)) || matches!(prefix(2), 36 | 38 | 39))
+                    && (14..=19).contains(&len)
+        }
+        // Discover 6011, 644–649, 65; UnionPay 62; Maestro 6x
+        b'6' => (12..=19).contains(&len),
+        _ => false,
+    }
+}
+
+fn is_card(number: &str) -> bool {
+    (12..=19).contains(&number.len()) && card_network(number) && checks::luhn(number)
+}
+
+static CARD: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d(?:[ -]?\d){11,18}\b"));
+
+fn payment_card(text: &str, findings: &mut Findings) {
+    for m in CARD.find_iter(text) {
+        if !stands_alone(text, m.start(), m.end()) {
+            continue;
+        }
+        let whole = digits(m.as_str());
+        if is_card(&whole) {
+            findings.insert(whole);
+            continue;
+        }
+        // Two numbers side by side ("4242 4242 4242 4242 2031"): try each
+        // run of whole groups
+        let groups: Vec<String> = m.as_str().split([' ', '-']).map(digits).collect();
+        'runs: for from in 0..groups.len() {
+            let mut number = String::new();
+            for group in &groups[from..] {
+                number.push_str(group);
+                if is_card(&number) {
+                    findings.insert(number);
+                    break 'runs;
+                }
+            }
+        }
+    }
+}
+
+// --- IBAN -----------------------------------------------------------------
+
+static IBAN: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b[A-Za-z]{2}\d{2}(?:[ ]?[A-Za-z0-9]){11,30}"));
+
+fn iban(text: &str, findings: &mut Findings) {
+    // The pattern can run on into the next words, even the next IBAN: after
+    // each hit, look again from where that IBAN ended
+    let mut from = 0;
+    while let Some(m) = IBAN.find_at(text, from) {
+        from = m.start() + 1;
+        let compact = m.as_str().replace(' ', "").to_ascii_uppercase();
+        let Some(len) = checks::iban_length(&compact[..2]) else {
+            continue;
+        };
+        if compact.len() < len {
+            continue;
+        }
+        // Where the country's length ends in the text, spaces counted
+        let mut seen = 0;
+        let Some(end) = m
+            .as_str()
+            .char_indices()
+            .find(|(_, c)| {
+                if *c != ' ' {
+                    seen += 1;
+                }
+                seen == len
+            })
+            .map(|(i, c)| m.start() + i + c.len_utf8())
+        else {
+            continue;
+        };
+        let candidate = &compact[..len];
+        if stands_alone(text, m.start(), end) && checks::iban(candidate) {
+            findings.insert(candidate);
+            from = end;
+        }
+    }
+}
+
+// --- SWIFT/BIC ------------------------------------------------------------
+
+static BIC: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b[A-Z]{4}[A-Z]{2}[A-Z0-9]{2}(?:[A-Z0-9]{3})?\b"));
+
+const BIC_WORDS: &[&str] = &[
+    "swift",
+    "bic",
+    "swift/bic",
+    "bank",
+    "banque",
+    "bankverbindung",
+];
+
+fn swift_bic(text: &str, findings: &mut Findings) {
+    for m in BIC.find_iter(text) {
+        let code = m.as_str();
+        if checks::is_country(&code[4..6]) && word_near(text, m.start(), m.end(), BIC_WORDS) {
+            findings.insert(code);
+        }
+    }
+}
+
+// --- Contact lists --------------------------------------------------------
+
+static EMAIL: LazyLock<Regex> =
+    LazyLock::new(|| re(r"(?i)\b[a-z0-9._%+-]+@[a-z0-9-]+(?:\.[a-z0-9-]+)*\.[a-z]{2,}\b"));
+
+fn email_addresses(text: &str, findings: &mut Findings) {
+    for m in EMAIL.find_iter(text) {
+        findings.insert(m.as_str().to_lowercase());
+    }
+}
+
+/// International form: found alone. National form: only with a word.
+static PHONE_INTL: LazyLock<Regex> = LazyLock::new(|| re(r"\+\d{1,3}(?:[ .-]?\(?\d{1,4}\)?){2,5}"));
+static PHONE_NATIONAL: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\(?\d{2,4}\)?[ .-]\d{3,4}[ .-]\d{3,4}"));
+
+const PHONE_WORDS: &[&str] = &[
+    "phone",
+    "tel",
+    "telephone",
+    "mobile",
+    "cell",
+    "fax",
+    "telefon",
+    "téléphone",
+    "teléfono",
+    "telefono",
+    "handy",
+    "portable",
+    "móvil",
+    "cellulare",
+    "mobiel",
+];
+
+fn phone_numbers(text: &str, findings: &mut Findings) {
+    let mut international = Vec::new();
+    for m in PHONE_INTL.find_iter(text) {
+        let number = digits(m.as_str());
+        if (8..=15).contains(&number.len()) && stands_alone(text, m.start() + 1, m.end()) {
+            findings.insert(number);
+            international.push(m.range());
+        }
+    }
+    for m in PHONE_NATIONAL.find_iter(text) {
+        let number = digits(m.as_str());
+        // Not the tail of an international number already counted
+        if international.iter().any(|r| r.contains(&m.start())) {
+            continue;
+        }
+        if (9..=11).contains(&number.len())
+            && stands_alone(text, m.start(), m.end())
+            && !text[..m.start()].ends_with('+')
+            && word_near(text, m.start(), m.end(), PHONE_WORDS)
+        {
+            findings.insert(number);
+        }
+    }
+}
+
+// --- Date of birth --------------------------------------------------------
+
+static DATE_ISO: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{4})-(\d{2})-(\d{2})\b"));
+static DATE_NUMERIC: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b(\d{1,2})[./-](\d{1,2})[./-](\d{4})\b"));
+static DATE_WORDS: LazyLock<Regex> = LazyLock::new(|| {
+    re(
+        r"(?i)\b(?:(\d{1,2})\s+(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)[a-z]*\.?,?\s+(\d{4})|(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)[a-z]*\.?\s+(\d{1,2}),?\s+(\d{4}))\b",
+    )
+});
+
+const BIRTH_WORDS: &[&str] = &[
+    "born",
+    "birth",
+    "dob",
+    "d.o.b",
+    "birthday",
+    "birthdate",
+    "geburtsdatum",
+    "geboren",
+    "naissance",
+    "né le",
+    "née le",
+    "nacimiento",
+    "nacido",
+    "nacida",
+    "nascita",
+    "nato il",
+    "nata il",
+    "geboortedatum",
+    "födelsedatum",
+    "fødselsdato",
+    "syntymäaika",
+    "urodzenia",
+    "nascimento",
+];
+
+fn month_number(name: &str) -> u32 {
+    const MONTHS: [&str; 12] = [
+        "jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec",
+    ];
+    let name = name.to_lowercase();
+    MONTHS
+        .iter()
+        .position(|m| *m == name)
+        .map_or(0, |i| i as u32 + 1)
+}
+
+fn date_of_birth(text: &str, findings: &mut Findings) {
+    let mut add = |start: usize, end: usize, key: String| {
+        if word_near(text, start, end, BIRTH_WORDS) {
+            findings.insert(key);
+        }
+    };
+    let num = |s: &str| s.parse::<u32>().unwrap_or(0);
+    for c in DATE_ISO.captures_iter(text) {
+        let (y, m, d) = (num(&c[1]), num(&c[2]), num(&c[3]));
+        let whole = c.get(0).unwrap();
+        if valid_date(y, m, d) {
+            add(whole.start(), whole.end(), format!("{y:04}{m:02}{d:02}"));
+        }
+    }
+    for c in DATE_NUMERIC.captures_iter(text) {
+        let (a, b, y) = (num(&c[1]), num(&c[2]), num(&c[3]));
+        let whole = c.get(0).unwrap();
+        // Day first or month first: either reading that is a real date
+        if valid_date(y, b, a) || valid_date(y, a, b) {
+            add(whole.start(), whole.end(), whole.as_str().to_string());
+        }
+    }
+    for c in DATE_WORDS.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let (d, m, y) = match (c.get(1), c.get(4)) {
+            (Some(d), _) => (num(d.as_str()), month_number(&c[2]), num(&c[3])),
+            (_, Some(m)) => (num(&c[5]), month_number(m.as_str()), num(&c[6])),
+            _ => continue,
+        };
+        if valid_date(y, m, d) {
+            add(whole.start(), whole.end(), format!("{y:04}{m:02}{d:02}"));
+        }
+    }
+}
+
+// --- Passport -------------------------------------------------------------
+
+static PASSPORT: LazyLock<Regex> = LazyLock::new(|| re(r"\b[A-Z0-9]{6,9}\b"));
+
+const PASSPORT_WORDS: &[&str] = &[
+    "passport",
+    "passeport",
+    "reisepass",
+    "pasaporte",
+    "passaporto",
+    "paspoort",
+    "passnummer",
+    "pass-nr",
+    "passport no",
+    "pasaporte n.º",
+    "passaporte",
+];
+
+fn passport(text: &str, findings: &mut Findings) {
+    for m in PASSPORT.find_iter(text) {
+        let value = m.as_str();
+        if value.bytes().filter(u8::is_ascii_digit).count() >= 5
+            && word_near(text, m.start(), m.end(), PASSPORT_WORDS)
+        {
+            findings.insert(value);
+        }
+    }
+}
+
+// --- Keys and credentials -------------------------------------------------
+
+static PRIVATE_KEY: LazyLock<Regex> = LazyLock::new(|| {
+    re(
+        r"-----BEGIN (?:(?:RSA|EC|DSA|OPENSSH|ENCRYPTED|PGP) )?PRIVATE KEY(?: BLOCK)?-----\s*([A-Za-z0-9+/=:\s-]{0,64})",
+    )
+});
+
+fn private_key(text: &str, findings: &mut Findings) {
+    for c in PRIVATE_KEY.captures_iter(text) {
+        // Each key once, by the start of its body
+        let body: String = c[1].chars().filter(|c| !c.is_whitespace()).collect();
+        let whole = c.get(0).unwrap();
+        findings.insert(if body.is_empty() {
+            format!("@{}", whole.start())
+        } else {
+            body
+        });
+    }
+}
+
+/// Published token formats: AWS access key IDs, GitHub tokens, Slack
+/// tokens, Stripe live secret and restricted keys, Google API keys.
+static CREDENTIAL: LazyLock<Regex> = LazyLock::new(|| {
+    re(concat!(
+        r"\b(?:",
+        r"(?:AKIA|ASIA|ABIA|ACCA)[A-Z0-9]{16}",
+        r"|gh[pousr]_[A-Za-z0-9]{36}",
+        r"|github_pat_[A-Za-z0-9_]{82}",
+        r"|xox[abposr]-[A-Za-z0-9-]{10,72}",
+        r"|(?:sk|rk)_live_[A-Za-z0-9]{24,99}",
+        r"|AIza[0-9A-Za-z_-]{35}",
+        r")\b"
+    ))
+});
+
+fn credentials(text: &str, findings: &mut Findings) {
+    for m in CREDENTIAL.find_iter(text) {
+        findings.insert(m.as_str());
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn payment_cards() {
+        // Networks' and processors' published test numbers
+        let text = "Visa 4242 4242 4242 4242, MC 5555-5555-5555-4444, Amex 378282246310005, \
+                    Discover 6011111111111117, JCB 3566002020360505, Diners 30569309025904, \
+                    UnionPay 6200000000000005, Mastercard 2-series 2223003122003222";
+        assert_eq!(count("payment-card", text), 8);
+        // Luhn fails, wrong network length, inside a longer number
+        assert_eq!(count("payment-card", "4242424242424241"), 0);
+        assert_eq!(count("payment-card", "378282246310005 0"), 1);
+        assert_eq!(count("payment-card", "order 94242424242424242 shipped"), 0);
+        // The same number twice counts once
+        assert_eq!(
+            count("payment-card", "4242424242424242 and 4242-4242-4242-4242"),
+            1
+        );
+        // A card followed by a year
+        assert_eq!(count("payment-card", "card 4242 4242 4242 4242 2031"), 1);
+    }
+
+    #[test]
+    fn ibans() {
+        let text =
+            "Pay GB29 NWBK 6016 1331 9268 19 or de89370400440532013000 (NL91ABNA0417164300).";
+        assert_eq!(count("iban", text), 3);
+        assert_eq!(count("iban", "GB29 NWBK 6016 1331 9268 18"), 0);
+        // Runs into the next word: still found at the country's length
+        assert_eq!(count("iban", "IBAN NL91ABNA0417164300 BIC ABNANL2A"), 1);
+    }
+
+    #[test]
+    fn swift_codes_need_a_word() {
+        assert_eq!(count("swift-bic", "SWIFT: DEUTDEFF500"), 1);
+        assert_eq!(count("swift-bic", "BIC NWBKGB2L"), 1);
+        assert_eq!(count("swift-bic", "HAPPYDAYS DEUTDEFF"), 0);
+        // Not a country in positions 5–6
+        assert_eq!(count("swift-bic", "BIC DEUTZZFF"), 0);
+    }
+
+    #[test]
+    fn email_and_phone_lists() {
+        let list = "[email protected], [email protected], [email protected], [email protected]";
+        assert_eq!(count("email-addresses", list), 3);
+        assert_eq!(
+            count("phone-numbers", "+44 20 7946 0958, +1 (415) 555-2671"),
+            2
+        );
+        assert_eq!(count("phone-numbers", "call 020 7946 0958"), 0);
+        assert_eq!(count("phone-numbers", "Tel: 020 7946 0958"), 1);
+        assert_eq!(count("phone-numbers", "invoice 020 7946 0958"), 0);
+        // One number, not also its national tail
+        assert_eq!(count("phone-numbers", "Tel: +44 20 7946 0958"), 1);
+    }
+
+    #[test]
+    fn dates_of_birth() {
+        assert_eq!(count("date-of-birth", "DOB: 1984-02-29"), 1);
+        assert_eq!(count("date-of-birth", "Geburtsdatum 31.12.1970"), 1);
+        assert_eq!(count("date-of-birth", "born on March 3, 1962"), 1);
+        assert_eq!(count("date-of-birth", "date of birth 3 Mar 1962"), 1);
+        // Not a real date, no word, a meeting
+        assert_eq!(count("date-of-birth", "DOB: 1985-02-29"), 0);
+        assert_eq!(count("date-of-birth", "invoice 1984-02-29"), 0);
+        assert_eq!(count("date-of-birth", "Meeting on 12/05/2026"), 0);
+    }
+
+    #[test]
+    fn passports_need_a_word() {
+        assert_eq!(count("passport", "Passport number: 533380006"), 1);
+        assert_eq!(count("passport", "Reisepass C01X00T47"), 1);
+        assert_eq!(count("passport", "Order 533380006 shipped"), 0);
+        // Mostly letters: a word, not a number
+        assert_eq!(count("passport", "passport PASSWORD"), 0);
+    }
+
+    #[test]
+    fn keys_and_credentials() {
+        let key = "-----BEGIN OPENSSH PRIVATE KEY-----\nb3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQ\n-----END OPENSSH PRIVATE KEY-----";
+        assert_eq!(count("private-key", key), 1);
+        assert_eq!(count("private-key", "-----BEGIN PUBLIC KEY-----\nMFkw"), 0);
+        // Documentation examples of each format
+        let tokens = "AKIAIOSFODNN7EXAMPLE ghp_0123456789abcdefghijklmnopqrstuvwxyz \
+                      AIzaSyA-0123456789abcdefghijklmnopqrstu";
+        assert_eq!(count("credentials", tokens), 3);
+        assert_eq!(count("credentials", "AKIA123 ghp_short"), 0);
+    }
+}

crates/features/src/mailflow/detectors/asia.rs

@@ -0,0 +1,281 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Asian identifiers (§2.3): India's Aadhaar and PAN, China's resident ID,
+//! Japan's My Number, Singapore's NRIC and FIN, and South Korea's resident
+//! registration number.
+
+use super::{
+    Detector, Findings, Region, Strength, digit_values, valid_date, valid_short_date, word_near,
+};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "in-aadhaar",
+        "India: Aadhaar",
+        Region::Asia,
+        Strength::Checked,
+        in_aadhaar,
+    ),
+    Detector::new(
+        "in-pan",
+        "India: PAN",
+        Region::Asia,
+        Strength::NeedsWord,
+        in_pan,
+    ),
+    Detector::new(
+        "cn-resident-id",
+        "China: resident ID",
+        Region::Asia,
+        Strength::Checked,
+        cn_resident_id,
+    ),
+    Detector::new(
+        "jp-my-number",
+        "Japan: My Number",
+        Region::Asia,
+        Strength::Checked,
+        jp_my_number,
+    ),
+    Detector::new(
+        "sg-nric",
+        "Singapore: NRIC and FIN",
+        Region::Asia,
+        Strength::Checked,
+        sg_nric,
+    ),
+    Detector::new(
+        "kr-rrn",
+        "South Korea: resident registration number",
+        Region::Asia,
+        Strength::NeedsWord,
+        kr_rrn,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+/// Twelve digits written in fours, or bare.
+static TWELVE: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{4})( ?)(\d{4})( ?)(\d{4})\b"));
+
+const VERHOEFF_D: [[u8; 10]; 10] = [
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
+    [1, 2, 3, 4, 0, 6, 7, 8, 9, 5],
+    [2, 3, 4, 0, 1, 7, 8, 9, 5, 6],
+    [3, 4, 0, 1, 2, 8, 9, 5, 6, 7],
+    [4, 0, 1, 2, 3, 9, 5, 6, 7, 8],
+    [5, 9, 8, 7, 6, 0, 4, 3, 2, 1],
+    [6, 5, 9, 8, 7, 1, 0, 4, 3, 2],
+    [7, 6, 5, 9, 8, 2, 1, 0, 4, 3],
+    [8, 7, 6, 5, 9, 3, 2, 1, 0, 4],
+    [9, 8, 7, 6, 5, 4, 3, 2, 1, 0],
+];
+const VERHOEFF_P: [[u8; 10]; 8] = [
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
+    [1, 5, 7, 6, 2, 8, 3, 0, 9, 4],
+    [5, 8, 0, 3, 7, 9, 6, 1, 4, 2],
+    [8, 9, 1, 6, 0, 4, 3, 5, 2, 7],
+    [9, 4, 5, 3, 1, 2, 6, 8, 7, 0],
+    [4, 2, 8, 6, 5, 7, 3, 9, 0, 1],
+    [2, 7, 9, 3, 8, 0, 6, 4, 1, 5],
+    [7, 0, 4, 6, 9, 1, 3, 2, 5, 8],
+];
+
+/// The Verhoeff check (dihedral group D5).
+pub fn verhoeff(n: &str) -> bool {
+    let mut c = 0u8;
+    for (i, b) in n.bytes().rev().enumerate() {
+        c = VERHOEFF_D[c as usize][VERHOEFF_P[i % 8][(b - b'0') as usize] as usize];
+    }
+    c == 0
+}
+
+const AADHAAR_WORDS: &[&str] = &["aadhaar", "aadhar", "uidai", "uid"];
+
+fn in_aadhaar(text: &str, findings: &mut Findings) {
+    for c in TWELVE.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = &c[2] == " " && &c[4] == " ";
+        // Never starts with 0 or 1
+        if !n.starts_with(['0', '1'])
+            && verhoeff(&n)
+            && (written || word_near(text, whole.start(), whole.end(), AADHAAR_WORDS))
+        {
+            findings.insert(n);
+        }
+    }
+}
+
+/// Five letters (the fourth names the holder's type), four digits, a letter.
+static PAN: LazyLock<Regex> = LazyLock::new(|| re(r"\b[A-Z]{3}[ABCFGHLJPTK][A-Z]\d{4}[A-Z]\b"));
+
+const PAN_WORDS: &[&str] = &["pan", "pan card", "permanent account number", "income tax"];
+
+fn in_pan(text: &str, findings: &mut Findings) {
+    for m in PAN.find_iter(text) {
+        if word_near(text, m.start(), m.end(), PAN_WORDS) {
+            findings.insert(m.as_str());
+        }
+    }
+}
+
+/// Region, birth date `YYYYMMDD`, sequence, then the ISO 7064 MOD 11-2
+/// check (0–9 or X).
+static CN_ID: LazyLock<Regex> =
+    LazyLock::new(|| re(r"(?i)\b[1-8]\d{5}(\d{4})(\d{2})(\d{2})\d{3}[\dX]\b"));
+
+pub fn cn_id_valid(id: &str) -> bool {
+    const WEIGHTS: [u32; 17] = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2];
+    const CHECKS: &[u8] = b"10X98765432";
+    let sum: u32 = digit_values(&id[..17])
+        .iter()
+        .zip(WEIGHTS)
+        .map(|(a, w)| a * w)
+        .sum();
+    CHECKS[(sum % 11) as usize] == id.as_bytes()[17].to_ascii_uppercase()
+}
+
+fn cn_resident_id(text: &str, findings: &mut Findings) {
+    for c in CN_ID.captures_iter(text) {
+        let id = c[0].to_ascii_uppercase();
+        let (y, m, d) = (num(&c[1]), num(&c[2]), num(&c[3]));
+        if valid_date(y, m, d) && cn_id_valid(&id) {
+            findings.insert(id);
+        }
+    }
+}
+
+/// My Number: weights 2–7 then 2–6 from the right; a remainder of 0 or 1
+/// gives 0, else 11 minus it.
+pub fn my_number_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    let sum: u32 = (1..=11)
+        .map(|i| d[11 - i] * if i <= 6 { i as u32 + 1 } else { i as u32 - 5 })
+        .sum();
+    let check = match sum % 11 {
+        0 | 1 => 0,
+        r => 11 - r,
+    };
+    check == d[11]
+}
+
+const MY_NUMBER_WORDS: &[&str] = &[
+    "my number",
+    "mynumber",
+    "マイナンバー",
+    "個人番号",
+    "kojin bango",
+];
+
+fn jp_my_number(text: &str, findings: &mut Findings) {
+    for c in TWELVE.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = &c[2] == " " && &c[4] == " ";
+        if my_number_valid(&n)
+            && (written || word_near(text, whole.start(), whole.end(), MY_NUMBER_WORDS))
+        {
+            findings.insert(n);
+        }
+    }
+}
+
+static NRIC: LazyLock<Regex> = LazyLock::new(|| re(r"(?i)\b([STFGM])(\d{7})([A-Z])\b"));
+
+/// Weights 2, 7, 6, 5, 4, 3, 2; T and G add 4, M adds 3; each series has its
+/// own table of check letters.
+fn nric_valid(prefix: u8, digits: &str, check: u8) -> bool {
+    let sum: u32 = digit_values(digits)
+        .iter()
+        .zip([2, 7, 6, 5, 4, 3, 2])
+        .map(|(a, w)| a * w)
+        .sum::<u32>()
+        + match prefix {
+            b'T' | b'G' => 4,
+            b'M' => 3,
+            _ => 0,
+        };
+    let table: &[u8] = match prefix {
+        b'S' | b'T' => b"JZIHGFEDCBA",
+        b'F' | b'G' => b"XWUTRQPNMLK",
+        _ => b"KLJNPQRTUWX",
+    };
+    table[(sum % 11) as usize] == check
+}
+
+fn sg_nric(text: &str, findings: &mut Findings) {
+    for c in NRIC.captures_iter(text) {
+        let id = c[0].to_ascii_uppercase();
+        let bytes = id.as_bytes();
+        if nric_valid(bytes[0], &c[2], bytes[8]) {
+            findings.insert(id);
+        }
+    }
+}
+
+/// `YYMMDD-GNNNNNN`, the seventh digit giving sex and century.
+static RRN: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{2})(\d{2})(\d{2})-?([1-8])\d{6}\b"));
+
+const RRN_WORDS: &[&str] = &["주민등록번호", "주민번호", "resident registration", "rrn"];
+
+fn kr_rrn(text: &str, findings: &mut Findings) {
+    for c in RRN.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        if valid_short_date(num(&c[1]), num(&c[2]), num(&c[3]))
+            && word_near(text, whole.start(), whole.end(), RRN_WORDS)
+        {
+            findings.insert(whole.as_str().replace('-', ""));
+        }
+    }
+}
+
+fn num(s: &str) -> u32 {
+    s.parse().unwrap_or(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn india() {
+        assert_eq!(count("in-aadhaar", "2345 6789 0124"), 1);
+        assert_eq!(count("in-aadhaar", "2345 6789 0125"), 0);
+        assert_eq!(count("in-aadhaar", "order 234567890124"), 0);
+        assert_eq!(count("in-aadhaar", "Aadhaar 234567890124"), 1);
+        assert_eq!(count("in-pan", "PAN: ABCPE1234F"), 1);
+        assert_eq!(count("in-pan", "ABCPE1234F"), 0);
+    }
+
+    #[test]
+    fn china_japan() {
+        assert_eq!(count("cn-resident-id", "11010519491231002X"), 1);
+        assert_eq!(count("cn-resident-id", "110105194912310021"), 0);
+        assert_eq!(count("cn-resident-id", "11010519491331002X"), 0);
+        assert_eq!(count("jp-my-number", "1234 5678 9018"), 1);
+        assert_eq!(count("jp-my-number", "1234 5678 9017"), 0);
+        assert_eq!(count("jp-my-number", "マイナンバー 123456789018"), 1);
+    }
+
+    #[test]
+    fn singapore_korea() {
+        assert_eq!(count("sg-nric", "S1234567D and T1234567J"), 2);
+        assert_eq!(count("sg-nric", "S1234567E"), 0);
+        assert_eq!(count("kr-rrn", "주민등록번호 800101-1234567"), 1);
+        assert_eq!(count("kr-rrn", "800101-1234567"), 0);
+        assert_eq!(count("kr-rrn", "RRN 801301-1234567"), 0);
+    }
+}

crates/features/src/mailflow/detectors/australia.rs

@@ -0,0 +1,128 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Australian identifiers (§2.3): the ATO's Tax File Number and the Medicare
+//! card number.
+
+use super::{Detector, Findings, Region, Strength, word_near};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "au-tfn",
+        "Australian Tax File Number",
+        Region::Australia,
+        Strength::Checked,
+        tfn,
+    ),
+    Detector::new(
+        "au-medicare",
+        "Australian Medicare number",
+        Region::Australia,
+        Strength::Checked,
+        medicare,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+/// `NNN NNN NNN` stands alone; bare digits (eight or nine) need a word.
+static TFN: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{3})( ?)(\d{3})( ?)(\d{2,3})\b"));
+
+/// Weighted sum mod 11, with the ATO's weights for 9- and 8-digit numbers.
+pub fn tfn_valid(n: &str) -> bool {
+    let weights: &[u32] = match n.len() {
+        9 => &[1, 4, 3, 7, 5, 8, 6, 9, 10],
+        8 => &[10, 7, 8, 4, 6, 3, 5, 1],
+        _ => return false,
+    };
+    n.bytes()
+        .zip(weights)
+        .map(|(b, w)| u32::from(b - b'0') * w)
+        .sum::<u32>()
+        % 11
+        == 0
+}
+
+const TFN_WORDS: &[&str] = &["tfn", "tax file number", "tax file no"];
+
+fn tfn(text: &str, findings: &mut Findings) {
+    for c in TFN.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = n.len() == 9 && c[2] == *" " && c[4] == *" ";
+        if tfn_valid(&n) && (written || word_near(text, whole.start(), whole.end(), TFN_WORDS)) {
+            findings.insert(n);
+        }
+    }
+}
+
+/// `NNNN NNNNN N` (and an optional issue number) stands alone; bare digits
+/// need a word.
+static MEDICARE: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b([2-6]\d{3})( ?)(\d{5})( ?)(\d)(?:[ -]?\d)?\b"));
+
+/// The ninth digit is the weighted sum (1, 3, 7, 9, 1, 3, 7, 9) of the first
+/// eight, mod 10.
+pub fn medicare_valid(n: &str) -> bool {
+    let d: Vec<u32> = n.bytes().map(|b| u32::from(b - b'0')).collect();
+    d.len() >= 9
+        && d[..8]
+            .iter()
+            .zip([1, 3, 7, 9, 1, 3, 7, 9])
+            .map(|(a, w)| a * w)
+            .sum::<u32>()
+            % 10
+            == d[8]
+}
+
+const MEDICARE_WORDS: &[&str] = &[
+    "medicare",
+    "medicare card",
+    "medicare no",
+    "medicare number",
+];
+
+fn medicare(text: &str, findings: &mut Findings) {
+    for c in MEDICARE.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = c[2] == *" " && c[4] == *" ";
+        if medicare_valid(&n)
+            && (written || word_near(text, whole.start(), whole.end(), MEDICARE_WORDS))
+        {
+            findings.insert(n);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn tax_file_numbers() {
+        assert_eq!(count("au-tfn", "TFN 123 456 782"), 1);
+        assert_eq!(count("au-tfn", "123 456 789"), 0);
+        assert_eq!(count("au-tfn", "order 123456782"), 0);
+        assert_eq!(count("au-tfn", "tax file number 123456782"), 1);
+    }
+
+    #[test]
+    fn medicare_numbers() {
+        assert_eq!(count("au-medicare", "2123 45670 1"), 1);
+        assert_eq!(count("au-medicare", "2123 45671 1"), 0);
+        assert_eq!(count("au-medicare", "ref 2123456701"), 0);
+        assert_eq!(count("au-medicare", "Medicare 2123456701"), 1);
+    }
+}

crates/features/src/mailflow/detectors/canada.rs

@@ -0,0 +1,66 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Canadian identifiers (§2.3): the Social Insurance Number.
+
+use super::{Detector, Findings, Region, Strength, checks, word_near};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[Detector::new(
+    "ca-sin",
+    "Canadian Social Insurance Number",
+    Region::Canada,
+    Strength::Checked,
+    sin,
+)];
+
+/// `NNN NNN NNN` or `NNN-NNN-NNN` stands alone; nine bare digits need a word.
+static SIN: LazyLock<Regex> = LazyLock::new(|| {
+    Regex::new(r"\b(\d{3})([ -]?)(\d{3})([ -]?)(\d{3})\b").expect("detector pattern")
+});
+
+const SIN_WORDS: &[&str] = &[
+    "sin",
+    "social insurance",
+    "nas",
+    "numéro d'assurance sociale",
+    "assurance sociale",
+];
+
+fn sin(text: &str, findings: &mut Findings) {
+    for c in SIN.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = !c[2].is_empty() && c[2] == c[4];
+        // 0 and 8 are never issued as a first digit
+        if !n.starts_with(['0', '8'])
+            && checks::luhn(&n)
+            && (written || word_near(text, whole.start(), whole.end(), SIN_WORDS))
+        {
+            findings.insert(n);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(text: &str) -> usize {
+        by_id("ca-sin").unwrap().count(text)
+    }
+
+    #[test]
+    fn social_insurance_numbers() {
+        assert_eq!(count("130 692 544 and 193-456-787"), 2);
+        assert_eq!(count("130 692 545"), 0);
+        // The government's printed example starts with 0, never issued
+        assert_eq!(count("046 454 286"), 0);
+        assert_eq!(count("order 130692544"), 0);
+        assert_eq!(count("SIN: 130692544"), 1);
+    }
+}

crates/features/src/mailflow/detectors/checks.rs

@@ -0,0 +1,227 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Check-digit algorithms, each from its public definition.
+
+/// The Luhn check (ISO/IEC 7812-1, Annex B) over a string of ASCII digits.
+pub fn luhn(digits: &str) -> bool {
+    if digits.len() < 2 || !digits.bytes().all(|b| b.is_ascii_digit()) {
+        return false;
+    }
+    let sum: u32 = digits
+        .bytes()
+        .rev()
+        .enumerate()
+        .map(|(i, b)| {
+            let d = u32::from(b - b'0');
+            if i % 2 == 1 {
+                let d = d * 2;
+                if d > 9 { d - 9 } else { d }
+            } else {
+                d
+            }
+        })
+        .sum();
+    sum.is_multiple_of(10)
+}
+
+/// ISO 13616 IBAN lengths, by country, from the IBAN registry.
+const IBAN_LENGTHS: &[(&str, usize)] = &[
+    ("AD", 24),
+    ("AE", 23),
+    ("AL", 28),
+    ("AT", 20),
+    ("AZ", 28),
+    ("BA", 20),
+    ("BE", 16),
+    ("BG", 22),
+    ("BH", 22),
+    ("BI", 27),
+    ("BR", 29),
+    ("BY", 28),
+    ("CH", 21),
+    ("CR", 22),
+    ("CY", 28),
+    ("CZ", 24),
+    ("DE", 22),
+    ("DJ", 27),
+    ("DK", 18),
+    ("DO", 28),
+    ("EE", 20),
+    ("EG", 29),
+    ("ES", 24),
+    ("FI", 18),
+    ("FK", 18),
+    ("FO", 18),
+    ("FR", 27),
+    ("GB", 22),
+    ("GE", 22),
+    ("GI", 23),
+    ("GL", 18),
+    ("GR", 27),
+    ("GT", 28),
+    ("HN", 28),
+    ("HR", 21),
+    ("HU", 28),
+    ("IE", 22),
+    ("IL", 23),
+    ("IQ", 23),
+    ("IS", 26),
+    ("IT", 27),
+    ("JO", 30),
+    ("KW", 30),
+    ("KZ", 20),
+    ("LB", 28),
+    ("LC", 32),
+    ("LI", 21),
+    ("LT", 20),
+    ("LU", 20),
+    ("LV", 21),
+    ("LY", 25),
+    ("MC", 27),
+    ("MD", 24),
+    ("ME", 22),
+    ("MK", 19),
+    ("MN", 20),
+    ("MR", 27),
+    ("MT", 31),
+    ("MU", 30),
+    ("NI", 28),
+    ("NL", 18),
+    ("NO", 15),
+    ("OM", 23),
+    ("PK", 24),
+    ("PL", 28),
+    ("PS", 29),
+    ("PT", 25),
+    ("QA", 29),
+    ("RO", 24),
+    ("RS", 22),
+    ("RU", 33),
+    ("SA", 24),
+    ("SC", 31),
+    ("SD", 18),
+    ("SE", 24),
+    ("SI", 19),
+    ("SK", 24),
+    ("SM", 27),
+    ("SO", 23),
+    ("ST", 25),
+    ("SV", 28),
+    ("TL", 23),
+    ("TN", 24),
+    ("TR", 26),
+    ("UA", 29),
+    ("VA", 22),
+    ("VG", 24),
+    ("XK", 20),
+    ("YE", 30),
+];
+
+/// The IBAN length for a country code, if the country uses IBANs.
+pub fn iban_length(country: &str) -> Option<usize> {
+    IBAN_LENGTHS
+        .iter()
+        .find(|(code, _)| *code == country)
+        .map(|(_, len)| *len)
+}
+
+/// ISO 13616 / ISO 7064 MOD 97-10 over an IBAN with no spaces, upper case:
+/// move the first four characters to the end, turn letters into 10–35, and
+/// the number mod 97 must be 1. Also checks the country's length.
+pub fn iban(iban: &str) -> bool {
+    if iban.len() < 5
+        || !iban
+            .bytes()
+            .all(|b| b.is_ascii_uppercase() || b.is_ascii_digit())
+    {
+        return false;
+    }
+    if iban_length(&iban[..2]) != Some(iban.len())
+        || !iban[2..4].bytes().all(|b| b.is_ascii_digit())
+    {
+        return false;
+    }
+    let mut remainder: u32 = 0;
+    for b in iban[4..].bytes().chain(iban[..4].bytes()) {
+        let value = if b.is_ascii_digit() {
+            u32::from(b - b'0')
+        } else {
+            u32::from(b - b'A') + 10
+        };
+        remainder = if value >= 10 {
+            (remainder * 100 + value) % 97
+        } else {
+            (remainder * 10 + value) % 97
+        };
+    }
+    remainder == 1
+}
+
+/// ISO 3166-1 alpha-2 country codes, for SWIFT/BIC positions 5–6.
+const COUNTRIES: &str = "AD AE AF AG AI AL AM AO AQ AR AS AT AU AW AX AZ BA BB BD BE BF BG BH BI BJ \
+BL BM BN BO BQ BR BS BT BV BW BY BZ CA CC CD CF CG CH CI CK CL CM CN CO CR CU CV CW CX CY CZ DE DJ \
+DK DM DO DZ EC EE EG EH ER ES ET FI FJ FK FM FO FR GA GB GD GE GF GG GH GI GL GM GN GP GQ GR GS GT \
+GU GW GY HK HM HN HR HT HU ID IE IL IM IN IO IQ IR IS IT JE JM JO JP KE KG KH KI KM KN KP KR KW KY \
+KZ LA LB LC LI LK LR LS LT LU LV LY MA MC MD ME MF MG MH MK ML MM MN MO MP MQ MR MS MT MU MV MW MX \
+MY MZ NA NC NE NF NG NI NL NO NP NR NU NZ OM PA PE PF PG PH PK PL PM PN PR PS PT PW PY QA RE RO RS \
+RU RW SA SB SC SD SE SG SH SI SJ SK SL SM SN SO SR SS ST SV SX SY SZ TC TD TF TG TH TJ TK TL TM TN \
+TO TR TT TV TW TZ UA UG UM US UY UZ VA VC VE VG VI VN VU WF WS XK YE YT ZA ZM ZW";
+
+pub fn is_country(code: &str) -> bool {
+    code.len() == 2 && COUNTRIES.split(' ').any(|c| c == code)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn luhn_known_numbers() {
+        // Published test card numbers
+        for good in [
+            "4242424242424242",
+            "5555555555554444",
+            "378282246310005",
+            "79927398713",
+        ] {
+            assert!(luhn(good), "{good}");
+        }
+        for bad in ["4242424242424241", "79927398710", "1", "12a4"] {
+            assert!(!luhn(bad), "{bad}");
+        }
+    }
+
+    #[test]
+    fn iban_registry_examples() {
+        // The IBAN registry's own examples
+        for good in [
+            "GB29NWBK60161331926819",
+            "DE89370400440532013000",
+            "FR1420041010050500013M02606",
+            "NL91ABNA0417164300",
+            "BE68539007547034",
+            "NO9386011117947",
+            "CH9300762011623852957",
+        ] {
+            assert!(iban(good), "{good}");
+        }
+        for bad in [
+            "GB29NWBK60161331926818", // check fails
+            "GB29NWBK6016133192681",  // too short for GB
+            "ZZ29NWBK60161331926819", // no such country
+            "DE8937040044053201300A", // letters where DE has none still fail mod 97
+        ] {
+            assert!(!iban(bad), "{bad}");
+        }
+    }
+
+    #[test]
+    fn countries() {
+        assert!(is_country("DE") && is_country("US") && is_country("XK"));
+        assert!(!is_country("ZZ") && !is_country("D"));
+    }
+}

crates/features/src/mailflow/detectors/eu.rs

@@ -0,0 +1,646 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! European Union national identifiers (§2.3), each from its issuer's
+//! published rules. An identifier that is only digits and whose check a
+//! random number passes often (mod 10, mod 11) counts alone only in its
+//! written form, and as bare digits only beside a word.
+
+use super::{
+    Detector, Findings, Region, Strength, checks, digit_values, stands_alone, valid_short_date,
+    word_near,
+};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "de-tax-id",
+        "Germany: tax ID (Steuer-ID)",
+        Region::Eu,
+        Strength::Checked,
+        de_tax_id,
+    ),
+    Detector::new(
+        "de-id-card",
+        "Germany: ID card number",
+        Region::Eu,
+        Strength::Checked,
+        de_id_card,
+    ),
+    Detector::new(
+        "fr-nir",
+        "France: social security number (NIR)",
+        Region::Eu,
+        Strength::Checked,
+        fr_nir,
+    ),
+    Detector::new(
+        "es-dni-nie",
+        "Spain: DNI and NIE",
+        Region::Eu,
+        Strength::Checked,
+        es_dni_nie,
+    ),
+    Detector::new(
+        "it-codice-fiscale",
+        "Italy: codice fiscale",
+        Region::Eu,
+        Strength::Checked,
+        it_codice_fiscale,
+    ),
+    Detector::new(
+        "nl-bsn",
+        "Netherlands: BSN",
+        Region::Eu,
+        Strength::Checked,
+        nl_bsn,
+    ),
+    Detector::new(
+        "be-national-number",
+        "Belgium: national number",
+        Region::Eu,
+        Strength::Checked,
+        be_national_number,
+    ),
+    Detector::new(
+        "pl-pesel",
+        "Poland: PESEL",
+        Region::Eu,
+        Strength::Checked,
+        pl_pesel,
+    ),
+    Detector::new(
+        "se-personnummer",
+        "Sweden: personnummer",
+        Region::Eu,
+        Strength::Checked,
+        se_personnummer,
+    ),
+    Detector::new(
+        "dk-cpr",
+        "Denmark: CPR number",
+        Region::Eu,
+        Strength::NeedsWord,
+        dk_cpr,
+    ),
+    Detector::new(
+        "fi-hetu",
+        "Finland: personal identity code",
+        Region::Eu,
+        Strength::Checked,
+        fi_hetu,
+    ),
+    Detector::new(
+        "ie-pps",
+        "Ireland: PPS number",
+        Region::Eu,
+        Strength::Checked,
+        ie_pps,
+    ),
+    Detector::new(
+        "pt-nif",
+        "Portugal: NIF",
+        Region::Eu,
+        Strength::Checked,
+        pt_nif,
+    ),
+    Detector::new(
+        "at-svnr",
+        "Austria: social insurance number",
+        Region::Eu,
+        Strength::Checked,
+        at_svnr,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+fn num(s: &str) -> u32 {
+    s.parse().unwrap_or(0)
+}
+
+// --- Germany --------------------------------------------------------------
+
+/// Eleven digits, written `86 095 742 719` on the BZSt's letters.
+static DE_TAX: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d{2}( ?)\d{3}( ?)\d{3}( ?)\d{3}\b"));
+
+/// ISO 7064 MOD 11,10; no leading zero; in the first ten digits one digit
+/// appears two or three times and every other at most once.
+pub fn de_tax_id_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    if d.len() != 11 || d[0] == 0 {
+        return false;
+    }
+    let mut counts = [0u8; 10];
+    for &x in &d[..10] {
+        counts[x as usize] += 1;
+    }
+    let repeated = counts.iter().filter(|&&c| c >= 2).count();
+    if repeated != 1 || counts.iter().any(|&c| c > 3) {
+        return false;
+    }
+    let mut product = 10;
+    for &x in &d[..10] {
+        let mut sum = (x + product) % 10;
+        if sum == 0 {
+            sum = 10;
+        }
+        product = (2 * sum) % 11;
+    }
+    let check = match 11 - product {
+        10 => 0,
+        c => c,
+    };
+    check == d[10]
+}
+
+const DE_TAX_WORDS: &[&str] = &[
+    "steuer-id",
+    "steueridentifikationsnummer",
+    "steuerliche identifikationsnummer",
+    "idnr",
+    "identifikationsnummer",
+    "tax id",
+];
+
+fn de_tax_id(text: &str, findings: &mut Findings) {
+    for c in DE_TAX.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let written = [&c[1], &c[2], &c[3]].iter().all(|s| *s == " ");
+        let n: String = whole.as_str().replace(' ', "");
+        if de_tax_id_valid(&n)
+            && (written || word_near(text, whole.start(), whole.end(), DE_TAX_WORDS))
+        {
+            findings.insert(n);
+        }
+    }
+}
+
+/// The ID card's document number: a letter from the card's alphabet, eight
+/// more characters from it, then the check digit.
+static DE_ID: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b[CFGHJKLMNPRTVWXYZ][CFGHJKLMNPRTVWXYZ0-9]{8}\d\b"));
+
+/// ICAO 9303 check digit: weights 7, 3, 1; letters A=10 … Z=35.
+pub fn icao_check(chars: &str, check: u32) -> bool {
+    let value = |c: char| c.to_digit(10).unwrap_or_else(|| c as u32 - 'A' as u32 + 10);
+    let sum: u32 = chars
+        .chars()
+        .zip([7, 3, 1].iter().cycle())
+        .map(|(c, w)| value(c) * w)
+        .sum();
+    sum % 10 == check
+}
+
+fn de_id_card(text: &str, findings: &mut Findings) {
+    for m in DE_ID.find_iter(text) {
+        let s = m.as_str();
+        if icao_check(&s[..9], num(&s[9..])) {
+            findings.insert(s);
+        }
+    }
+}
+
+// --- France ---------------------------------------------------------------
+
+/// Sex, year, month, department (with Corsica's 2A and 2B), commune, order,
+/// then the two-digit key, spaces allowed between groups.
+static FR_NIR: LazyLock<Regex> = LazyLock::new(|| {
+    re(r"\b([1-478]) ?(\d{2}) ?(\d{2}) ?(\d{2}|2[AB]) ?(\d{3}) ?(\d{3}) ?(\d{2})\b")
+});
+
+fn fr_nir(text: &str, findings: &mut Findings) {
+    for c in FR_NIR.captures_iter(text) {
+        let month = num(&c[3]);
+        if !(matches!(month, 1..=12 | 20..=42 | 50..=99)) {
+            continue;
+        }
+        let department = match &c[4] {
+            "2A" => "19",
+            "2B" => "18",
+            d => d,
+        };
+        let body = format!(
+            "{}{}{}{}{}{}",
+            &c[1], &c[2], &c[3], department, &c[5], &c[6]
+        );
+        let Ok(value) = body.parse::<u64>() else {
+            continue;
+        };
+        if 97 - value % 97 == u64::from(num(&c[7])) {
+            findings.insert(format!(
+                "{}{}{}{}{}{}{}",
+                &c[1], &c[2], &c[3], &c[4], &c[5], &c[6], &c[7]
+            ));
+        }
+    }
+}
+
+// --- Spain ----------------------------------------------------------------
+
+static ES_ID: LazyLock<Regex> = LazyLock::new(|| re(r"(?i)\b([XYZ]?)[ -]?(\d{7,8})[ -]?([A-Z])\b"));
+
+const DNI_LETTERS: &[u8] = b"TRWAGMYFPDXBNJZSQVHLCKE";
+
+fn es_dni_nie(text: &str, findings: &mut Findings) {
+    for c in ES_ID.captures_iter(text) {
+        let prefix = c[1].to_ascii_uppercase();
+        let digits = &c[2];
+        // DNI: eight digits; NIE: X, Y or Z and seven digits
+        let number = match (prefix.as_str(), digits.len()) {
+            ("", 8) => digits.to_string(),
+            ("X", 7) => format!("0{digits}"),
+            ("Y", 7) => format!("1{digits}"),
+            ("Z", 7) => format!("2{digits}"),
+            _ => continue,
+        };
+        let letter = c[3].to_ascii_uppercase();
+        if DNI_LETTERS[(num(&number) % 23) as usize] == letter.as_bytes()[0] {
+            findings.insert(format!("{prefix}{digits}{letter}"));
+        }
+    }
+}
+
+// --- Italy ----------------------------------------------------------------
+
+/// Surname and name letters, year, month letter, day, place code, check
+/// letter; digits may be replaced by letters (omocodia).
+static IT_CF: LazyLock<Regex> = LazyLock::new(|| {
+    let d = "[0-9LMNPQRSTUV]";
+    re(&format!(
+        r"(?i)\b[A-Z]{{6}}{d}{{2}}[ABCDEHLMPRST]{d}{{2}}[A-Z]{d}{{3}}[A-Z]\b"
+    ))
+});
+
+/// The Ministry's odd-position values for 0–9 and A–Z.
+const CF_ODD: [u32; 36] = [
+    1, 0, 5, 7, 9, 13, 15, 17, 19, 21, // 0-9
+    1, 0, 5, 7, 9, 13, 15, 17, 19, 21, 2, 4, 18, 20, 11, 3, 6, 8, 12, 14, 16, 10, 22, 25, 24,
+    23, // A-Z
+];
+
+pub fn codice_fiscale_valid(cf: &str) -> bool {
+    let index = |c: u8| {
+        if c.is_ascii_digit() {
+            (c - b'0') as usize
+        } else {
+            (c - b'A') as usize + 10
+        }
+    };
+    let even = |c: u8| {
+        if c.is_ascii_digit() {
+            u32::from(c - b'0')
+        } else {
+            u32::from(c - b'A')
+        }
+    };
+    let bytes = cf.as_bytes();
+    let sum: u32 = bytes[..15]
+        .iter()
+        .enumerate()
+        .map(|(i, &c)| {
+            if i % 2 == 0 {
+                CF_ODD[index(c)]
+            } else {
+                even(c)
+            }
+        })
+        .sum();
+    u32::from(bytes[15] - b'A') == sum % 26
+}
+
+fn it_codice_fiscale(text: &str, findings: &mut Findings) {
+    for m in IT_CF.find_iter(text) {
+        let cf = m.as_str().to_ascii_uppercase();
+        if codice_fiscale_valid(&cf) {
+            findings.insert(cf);
+        }
+    }
+}
+
+// --- Netherlands ----------------------------------------------------------
+
+/// Nine digits, sometimes written `1112.22.333`.
+static NL_BSN: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{4})(\.?)(\d{2})(\.?)(\d{3})\b"));
+
+/// The eleven test: weights 9 down to 2, and −1 for the last digit.
+pub fn bsn_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    let sum: i64 = d[..8]
+        .iter()
+        .zip((2..=9).rev())
+        .map(|(a, w)| i64::from(a * w))
+        .sum::<i64>()
+        - i64::from(d[8]);
+    sum != 0 && sum % 11 == 0
+}
+
+const BSN_WORDS: &[&str] = &[
+    "bsn",
+    "burgerservicenummer",
+    "sofinummer",
+    "sofi-nummer",
+    "citizen service number",
+];
+
+fn nl_bsn(text: &str, findings: &mut Findings) {
+    for c in NL_BSN.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = &c[2] == "." && &c[4] == ".";
+        if bsn_valid(&n) && (written || word_near(text, whole.start(), whole.end(), BSN_WORDS)) {
+            findings.insert(n);
+        }
+    }
+}
+
+// --- Belgium --------------------------------------------------------------
+
+/// `YY.MM.DD-XXX.CC` or eleven digits.
+static BE_NN: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b(\d{2})\.?(\d{2})\.?(\d{2})-?(\d{3})\.?(\d{2})\b"));
+
+fn be_national_number(text: &str, findings: &mut Findings) {
+    for c in BE_NN.captures_iter(text) {
+        let (month, day) = (num(&c[2]), num(&c[3]));
+        // Month 0 and day 0 mean unknown; bis numbers add 20 or 40 to the month
+        if !(month <= 12 || (20..=32).contains(&month) || (40..=52).contains(&month)) || day > 31 {
+            continue;
+        }
+        let body = format!("{}{}{}{}", &c[1], &c[2], &c[3], &c[4]);
+        let check = u64::from(num(&c[5]));
+        let before_2000 = 97 - body.parse::<u64>().unwrap_or(0) % 97;
+        let since_2000 = 97 - format!("2{body}").parse::<u64>().unwrap_or(0) % 97;
+        if check == before_2000 || check == since_2000 {
+            findings.insert(format!("{body}{}", &c[5]));
+        }
+    }
+}
+
+// --- Poland ---------------------------------------------------------------
+
+static ELEVEN: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d{11}\b"));
+
+/// Weights 1, 3, 7, 9 repeating; the birth date encodes the century in the
+/// month (+80 for the 1800s, +20 for the 2000s, and so on).
+pub fn pesel_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    let sum: u32 = d[..10]
+        .iter()
+        .zip([1, 3, 7, 9].iter().cycle())
+        .map(|(a, w)| a * w)
+        .sum();
+    let month = d[2] * 10 + d[3];
+    let (century, month) = match month {
+        81..=92 => (1800, month - 80),
+        1..=12 => (1900, month),
+        21..=32 => (2000, month - 20),
+        41..=52 => (2100, month - 40),
+        _ => return false,
+    };
+    let year = century + d[0] * 10 + d[1];
+    (10 - sum % 10) % 10 == d[10] && (1..=super::days_in(year, month)).contains(&(d[4] * 10 + d[5]))
+}
+
+const PESEL_WORDS: &[&str] = &["pesel", "numer pesel", "nr pesel"];
+
+fn pl_pesel(text: &str, findings: &mut Findings) {
+    for m in ELEVEN.find_iter(text) {
+        if pesel_valid(m.as_str()) && word_near(text, m.start(), m.end(), PESEL_WORDS) {
+            findings.insert(m.as_str());
+        }
+    }
+}
+
+// --- Sweden ---------------------------------------------------------------
+
+/// `YYMMDD-NNNN`, `YYYYMMDD-NNNN` (`+` after 100), or the bare digits.
+static SE_PNR: LazyLock<Regex> =
+    LazyLock::new(|| re(r"\b(?:\d{2})?(\d{2})(\d{2})(\d{2})([-+]?)(\d{4})\b"));
+
+const SE_WORDS: &[&str] = &[
+    "personnummer",
+    "personnr",
+    "person nr",
+    "samordningsnummer",
+    "pnr",
+];
+
+fn se_personnummer(text: &str, findings: &mut Findings) {
+    for c in SE_PNR.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let (yy, month, day) = (num(&c[1]), num(&c[2]), num(&c[3]));
+        // Coordination numbers add 60 to the day
+        let day = if day > 60 { day - 60 } else { day };
+        let ten = format!("{}{}{}{}", &c[1], &c[2], &c[3], &c[5]);
+        let written = !c[4].is_empty();
+        if valid_short_date(yy, month, day)
+            && checks::luhn(&ten)
+            && (written || word_near(text, whole.start(), whole.end(), SE_WORDS))
+        {
+            findings.insert(ten);
+        }
+    }
+}
+
+// --- Denmark --------------------------------------------------------------
+
+static DK_CPR: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{2})(\d{2})(\d{2})-?(\d{4})\b"));
+
+const CPR_WORDS: &[&str] = &["cpr", "cpr-nr", "cpr nr", "cpr-nummer", "personnummer"];
+
+fn dk_cpr(text: &str, findings: &mut Findings) {
+    for c in DK_CPR.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        if valid_short_date(num(&c[3]), num(&c[2]), num(&c[1]))
+            && word_near(text, whole.start(), whole.end(), CPR_WORDS)
+        {
+            findings.insert(whole.as_str().replace('-', ""));
+        }
+    }
+}
+
+// --- Finland --------------------------------------------------------------
+
+static FI_HETU: LazyLock<Regex> =
+    LazyLock::new(|| re(r"(?i)\b(\d{2})(\d{2})(\d{2})[-+ABCDEFYXWVU](\d{3})([0-9A-Y])\b"));
+
+const HETU_CHECK: &[u8] = b"0123456789ABCDEFHJKLMNPRSTUVWXY";
+
+fn fi_hetu(text: &str, findings: &mut Findings) {
+    for c in FI_HETU.captures_iter(text) {
+        let (day, month, yy) = (num(&c[1]), num(&c[2]), num(&c[3]));
+        let n: u64 = format!("{}{}{}{}", &c[1], &c[2], &c[3], &c[4])
+            .parse()
+            .unwrap_or(0);
+        let check = c[5].to_ascii_uppercase().as_bytes()[0];
+        if valid_short_date(yy, month, day) && HETU_CHECK[(n % 31) as usize] == check {
+            findings.insert(c[0].to_ascii_uppercase());
+        }
+    }
+}
+
+// --- Ireland --------------------------------------------------------------
+
+static IE_PPS: LazyLock<Regex> = LazyLock::new(|| re(r"(?i)\b(\d{7})([A-W])([ABHW]?)\b"));
+
+const PPS_CHECK: &[u8] = b"WABCDEFGHIJKLMNOPQRSTUV";
+
+fn ie_pps(text: &str, findings: &mut Findings) {
+    for c in IE_PPS.captures_iter(text) {
+        let mut sum: u32 = digit_values(&c[1])
+            .iter()
+            .zip((2..=8).rev())
+            .map(|(a, w)| a * w)
+            .sum();
+        // The second letter counts, times 9; W (the old form) counts as 0
+        let second = c[3].to_ascii_uppercase();
+        if let Some(&letter) = second.as_bytes().first()
+            && letter != b'W'
+        {
+            sum += u32::from(letter - b'A' + 1) * 9;
+        }
+        let check = c[2].to_ascii_uppercase().as_bytes()[0];
+        if PPS_CHECK[(sum % 23) as usize] == check {
+            findings.insert(c[0].to_ascii_uppercase());
+        }
+    }
+}
+
+// --- Portugal -------------------------------------------------------------
+
+static NINE: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d{9}\b"));
+
+/// Mod 11 over weights 9 down to 2; a check of 10 or 11 becomes 0.
+pub fn nif_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    let sum: u32 = d[..8].iter().zip((2..=9).rev()).map(|(a, w)| a * w).sum();
+    let check = match 11 - sum % 11 {
+        10 | 11 => 0,
+        c => c,
+    };
+    matches!(d[0], 1 | 2 | 3 | 5 | 6 | 8 | 9) && check == d[8]
+}
+
+const NIF_WORDS: &[&str] = &[
+    "nif",
+    "contribuinte",
+    "número de identificação fiscal",
+    "numero de contribuinte",
+];
+
+fn pt_nif(text: &str, findings: &mut Findings) {
+    for m in NINE.find_iter(text) {
+        if nif_valid(m.as_str()) && word_near(text, m.start(), m.end(), NIF_WORDS) {
+            findings.insert(m.as_str());
+        }
+    }
+}
+
+// --- Austria --------------------------------------------------------------
+
+/// A serial and check digit, then the birth date: `1237 010180`.
+static AT_SVNR: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{3})(\d)( ?)(\d{2})(\d{2})(\d{2})\b"));
+
+const SVNR_WORDS: &[&str] = &[
+    "sozialversicherungsnummer",
+    "svnr",
+    "sv-nr",
+    "sv-nummer",
+    "versicherungsnummer",
+];
+
+fn at_svnr(text: &str, findings: &mut Findings) {
+    for c in AT_SVNR.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}{}{}", &c[1], &c[2], &c[4], &c[5], &c[6]);
+        let d = digit_values(&n);
+        let sum: u32 = d
+            .iter()
+            .zip([3, 7, 9, 0, 5, 8, 4, 2, 1, 6])
+            .map(|(a, w)| a * w)
+            .sum();
+        let written = &c[3] == " ";
+        if d[0] != 0
+            && sum % 11 == d[3]
+            && valid_short_date(num(&c[6]), num(&c[5]), num(&c[4]))
+            && (written || word_near(text, whole.start(), whole.end(), SVNR_WORDS))
+            && stands_alone(text, whole.start(), whole.end())
+        {
+            findings.insert(n);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn germany() {
+        assert_eq!(count("de-tax-id", "86 095 742 719"), 1);
+        assert_eq!(count("de-tax-id", "Steuer-ID: 86095742719"), 1);
+        assert_eq!(count("de-tax-id", "Rechnung 86095742719"), 0);
+        assert_eq!(count("de-tax-id", "86 095 742 718"), 0);
+        // ICAO 9303's German specimen card
+        assert_eq!(count("de-id-card", "Ausweis T220001293"), 1);
+        assert_eq!(count("de-id-card", "T220001294"), 0);
+    }
+
+    #[test]
+    fn france_spain_italy() {
+        assert_eq!(count("fr-nir", "2 55 08 14 168 025 38"), 1);
+        assert_eq!(count("fr-nir", "255081416802539"), 0);
+        assert_eq!(count("es-dni-nie", "DNI 12345678Z, NIE X-1234567-L"), 2);
+        assert_eq!(count("es-dni-nie", "12345678A"), 0);
+        assert_eq!(count("it-codice-fiscale", "CF: RSSMRA85T10A562S"), 1);
+        assert_eq!(count("it-codice-fiscale", "RSSMRA85T10A562T"), 0);
+    }
+
+    #[test]
+    fn benelux() {
+        assert_eq!(count("nl-bsn", "1112.22.333"), 1);
+        assert_eq!(count("nl-bsn", "BSN 111222333"), 1);
+        assert_eq!(count("nl-bsn", "order 111222333"), 0);
+        assert_eq!(count("nl-bsn", "BSN 111222334"), 0);
+        assert_eq!(count("be-national-number", "85.07.30-033.28"), 1);
+        assert_eq!(count("be-national-number", "85073003329"), 0);
+    }
+
+    #[test]
+    fn nordics() {
+        assert_eq!(count("se-personnummer", "811218-9876"), 1);
+        assert_eq!(count("se-personnummer", "811218-9875"), 0);
+        assert_eq!(count("se-personnummer", "order 8112189876"), 0);
+        assert_eq!(count("se-personnummer", "personnummer 198112189876"), 1);
+        assert_eq!(count("dk-cpr", "CPR-nr: 010170-1234"), 1);
+        assert_eq!(count("dk-cpr", "010170-1234"), 0);
+        assert_eq!(count("dk-cpr", "CPR 320170-1234"), 0);
+        assert_eq!(count("fi-hetu", "131052-308T"), 1);
+        assert_eq!(count("fi-hetu", "131052-308U"), 0);
+    }
+
+    #[test]
+    fn poland_ireland_portugal_austria() {
+        assert_eq!(count("pl-pesel", "PESEL 44051401359, pesel 02070803628"), 2);
+        assert_eq!(count("pl-pesel", "PESEL 44051401358"), 0);
+        assert_eq!(count("pl-pesel", "44051401359"), 0);
+        assert_eq!(count("ie-pps", "PPS 1234567T and 1234567FA"), 2);
+        assert_eq!(count("ie-pps", "1234567U"), 0);
+        assert_eq!(count("pt-nif", "NIF 123456789"), 1);
+        assert_eq!(count("pt-nif", "NIF 123456788"), 0);
+        assert_eq!(count("at-svnr", "1237 010180"), 1);
+        assert_eq!(count("at-svnr", "SVNR 1237010180"), 1);
+        assert_eq!(count("at-svnr", "1238 010180"), 0);
+    }
+}

crates/features/src/mailflow/detectors/europe.rs

@@ -0,0 +1,116 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! European identifiers outside the EU (§2.3): Norway's national identity
+//! number and Switzerland's AHV number.
+
+use super::{Detector, Findings, Region, Strength, digit_values, valid_short_date};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "no-fnr",
+        "Norway: national identity number",
+        Region::Europe,
+        Strength::Checked,
+        no_fnr,
+    ),
+    Detector::new(
+        "ch-ahv",
+        "Switzerland: AHV number",
+        Region::Europe,
+        Strength::Checked,
+        ch_ahv,
+    ),
+];
+
+static ELEVEN: LazyLock<Regex> =
+    LazyLock::new(|| Regex::new(r"\b\d{6} ?\d{5}\b").expect("detector pattern"));
+
+/// Two mod 11 check digits over a birth date (D-numbers add 40 to the day,
+/// H-numbers 40 to the month): strong enough to count alone.
+pub fn fnr_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    if d.len() != 11 {
+        return false;
+    }
+    let check =
+        |weights: &[u32]| match 11 - d.iter().zip(weights).map(|(a, w)| a * w).sum::<u32>() % 11 {
+            11 => Some(0),
+            10 => None,
+            c => Some(c),
+        };
+    let day = d[0] * 10 + d[1];
+    let month = d[2] * 10 + d[3];
+    let day = if day > 40 { day - 40 } else { day };
+    let month = if month > 40 { month - 40 } else { month };
+    valid_short_date(d[4] * 10 + d[5], month, day)
+        && check(&[3, 7, 6, 1, 8, 9, 4, 5, 2]) == Some(d[9])
+        && check(&[5, 4, 3, 2, 7, 6, 5, 4, 3, 2]) == Some(d[10])
+}
+
+fn no_fnr(text: &str, findings: &mut Findings) {
+    for m in ELEVEN.find_iter(text) {
+        let n = m.as_str().replace(' ', "");
+        if fnr_valid(&n) {
+            findings.insert(n);
+        }
+    }
+}
+
+/// `756.1234.5678.97`: the country prefix, then an EAN-13 check digit.
+static AHV: LazyLock<Regex> = LazyLock::new(|| {
+    Regex::new(r"\b756[. ]?\d{4}[. ]?\d{4}[. ]?\d{2}\b").expect("detector pattern")
+});
+
+pub fn ean13_valid(n: &str) -> bool {
+    let d = digit_values(n);
+    if d.len() != 13 {
+        return false;
+    }
+    let sum: u32 = d[..12]
+        .iter()
+        .enumerate()
+        .map(|(i, x)| if i % 2 == 0 { *x } else { x * 3 })
+        .sum();
+    (10 - sum % 10) % 10 == d[12]
+}
+
+fn ch_ahv(text: &str, findings: &mut Findings) {
+    for m in AHV.find_iter(text) {
+        let n: String = m.as_str().chars().filter(char::is_ascii_digit).collect();
+        if ean13_valid(&n) {
+            findings.insert(n);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn norway() {
+        assert_eq!(count("no-fnr", "01019000083"), 1);
+        assert_eq!(count("no-fnr", "010190 00083"), 1);
+        assert_eq!(count("no-fnr", "01019000084"), 0);
+        // Not a date
+        assert_eq!(count("no-fnr", "32019000083"), 0);
+    }
+
+    #[test]
+    fn switzerland() {
+        // The federal example
+        assert_eq!(count("ch-ahv", "AHV 756.9217.0769.85"), 1);
+        assert_eq!(count("ch-ahv", "7569217076985"), 1);
+        assert_eq!(count("ch-ahv", "756.9217.0769.86"), 0);
+    }
+}

crates/features/src/mailflow/detectors/mod.rs

@@ -0,0 +1,278 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Detectors (dlp-and-mail-flow-rules spec, §2.3): each finds one kind of
+//! identifier in text and reports the distinct ones it found.
+//!
+//! A detector is one of two strengths:
+//!
+//! - **Checked**: the identifier carries a published check digit or
+//!   checksum, so a random number rarely passes; found on its own.
+//! - **Needs a word**: the format alone is too common, so a candidate counts
+//!   only with a corroborating word within [`WINDOW`] characters either
+//!   side.
+//!
+//! Findings are distinct normalized values (digits only, upper case), so the
+//! same card number pasted twice counts once. They stay in memory: callers
+//! read only [`Findings::len`].
+
+pub mod africa;
+pub mod americas;
+pub mod any;
+pub mod asia;
+pub mod australia;
+pub mod canada;
+pub mod checks;
+pub mod eu;
+pub mod europe;
+pub mod templates;
+pub mod uk;
+pub mod us;
+
+use ahash::AHashSet;
+
+/// How far, in characters, a corroborating word may be from a candidate.
+pub const WINDOW: usize = 50;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Strength {
+    Checked,
+    NeedsWord,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Region {
+    Any,
+    Us,
+    Uk,
+    Canada,
+    Australia,
+    Eu,
+    Europe,
+    Asia,
+    Americas,
+    Africa,
+}
+
+/// The distinct values one detector found.
+#[derive(Debug, Default)]
+pub struct Findings(AHashSet<String>);
+
+impl Findings {
+    pub fn insert(&mut self, value: impl Into<String>) {
+        self.0.insert(value.into());
+    }
+
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+}
+
+pub struct Detector {
+    /// Stable id, stored in rules: `payment-card`, `iban`, `us-ssn`.
+    pub id: &'static str,
+    pub name: &'static str,
+    pub region: Region,
+    pub strength: Strength,
+    find: fn(&str, &mut Findings),
+}
+
+impl Detector {
+    pub const fn new(
+        id: &'static str,
+        name: &'static str,
+        region: Region,
+        strength: Strength,
+        find: fn(&str, &mut Findings),
+    ) -> Self {
+        Self {
+            id,
+            name,
+            region,
+            strength,
+            find,
+        }
+    }
+
+    /// Adds what this detector finds in `text` to `findings`. Call once per
+    /// piece of text (subject, each part, each attachment) with the same
+    /// `findings`, then read its length.
+    pub fn find(&self, text: &str, findings: &mut Findings) {
+        (self.find)(text, findings)
+    }
+
+    /// The distinct values found in one text.
+    pub fn count(&self, text: &str) -> usize {
+        let mut findings = Findings::default();
+        self.find(text, &mut findings);
+        findings.len()
+    }
+}
+
+/// Every detector, in the order the console lists them.
+pub fn all() -> impl Iterator<Item = &'static Detector> {
+    [
+        any::DETECTORS,
+        us::DETECTORS,
+        uk::DETECTORS,
+        canada::DETECTORS,
+        australia::DETECTORS,
+        eu::DETECTORS,
+        europe::DETECTORS,
+        asia::DETECTORS,
+        americas::DETECTORS,
+        africa::DETECTORS,
+    ]
+    .into_iter()
+    .flatten()
+}
+
+pub fn by_id(id: &str) -> Option<&'static Detector> {
+    all().find(|detector| detector.id == id)
+}
+
+/// Whether one of `words` appears, as a whole word and ignoring case, within
+/// [`WINDOW`] characters before `start` or after `end` (byte offsets of the
+/// candidate in `text`). The window is widened by the longest word, so a
+/// word that reaches into it still counts whole.
+pub fn word_near(text: &str, start: usize, end: usize, words: &[&str]) -> bool {
+    let reach = WINDOW + words.iter().map(|w| w.chars().count()).max().unwrap_or(0);
+    let before = text[..start]
+        .char_indices()
+        .rev()
+        .nth(reach - 1)
+        .map_or(0, |(i, _)| i);
+    let after = text[end..]
+        .char_indices()
+        .nth(reach)
+        .map_or(text.len(), |(i, _)| end + i);
+    let window = text[before..after].to_lowercase();
+    words.iter().any(|word| contains_word(&window, word))
+}
+
+/// Whether `word` (lower case) appears in `haystack` (lower case) with no
+/// letter or digit on either side.
+pub fn contains_word(haystack: &str, word: &str) -> bool {
+    haystack.match_indices(word).any(|(i, _)| {
+        let before_ok = haystack[..i]
+            .chars()
+            .next_back()
+            .is_none_or(|c| !c.is_alphanumeric());
+        let after_ok = haystack[i + word.len()..]
+            .chars()
+            .next()
+            .is_none_or(|c| !c.is_alphanumeric());
+        before_ok && after_ok
+    })
+}
+
+/// Whether the match at `start..end` stands alone: no digit or letter
+/// directly before or after it, so `123-45-6789` isn't found inside a
+/// longer run of digits.
+pub fn stands_alone(text: &str, start: usize, end: usize) -> bool {
+    let before = text[..start].chars().next_back();
+    let after = text[end..].chars().next();
+    before.is_none_or(|c| !c.is_alphanumeric()) && after.is_none_or(|c| !c.is_alphanumeric())
+}
+
+/// Days in `month` of `year` (0 for a month that doesn't exist).
+pub fn days_in(year: u32, month: u32) -> u32 {
+    match month {
+        1 | 3 | 5 | 7 | 8 | 10 | 12 => 31,
+        4 | 6 | 9 | 11 => 30,
+        2 if year.is_multiple_of(4) && (!year.is_multiple_of(100) || year.is_multiple_of(400)) => {
+            29
+        }
+        2 => 28,
+        _ => 0,
+    }
+}
+
+/// Whether `year`-`month`-`day` is a real date between 1900 and 2100.
+pub fn valid_date(year: u32, month: u32, day: u32) -> bool {
+    (1900..=2100).contains(&year) && (1..=days_in(year, month)).contains(&day)
+}
+
+/// Whether a two-digit year, month and day make a real date in either the
+/// 1900s or the 2000s.
+pub fn valid_short_date(yy: u32, month: u32, day: u32) -> bool {
+    valid_date(1900 + yy, month, day) || valid_date(2000 + yy, month, day)
+}
+
+/// The value of each digit in `s`.
+pub fn digit_values(s: &str) -> Vec<u32> {
+    s.bytes()
+        .filter(u8::is_ascii_digit)
+        .map(|b| u32::from(b - b'0'))
+        .collect()
+}
+
+/// The ASCII digits of `s`.
+pub fn digits(s: &str) -> String {
+    s.chars().filter(char::is_ascii_digit).collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn words_are_whole_and_near() {
+        let text = "Your passport number is X1234567, thanks";
+        let start = text.find("X123").unwrap();
+        assert!(word_near(text, start, start + 8, &["passport"]));
+        assert!(!word_near(text, start, start + 8, &["pass"]));
+        let far = format!("passport{}X1234567", " ".repeat(60));
+        let start = far.find("X123").unwrap();
+        assert!(!word_near(&far, start, start + 8, &["passport"]));
+    }
+
+    #[test]
+    fn near_counts_characters_not_bytes() {
+        // 45 two-byte characters between the word and the candidate: within
+        // 50 characters, though over 50 bytes
+        let text = format!("passport {} X1234567", "é".repeat(45));
+        let start = text.find("X123").unwrap();
+        assert!(word_near(&text, start, start + 8, &["passport"]));
+    }
+
+    /// An ordinary business email: order, invoice and tracking numbers,
+    /// dates, amounts, a street address. Nothing here is an identifier, so
+    /// no detector may fire, except the contact ones on the signature.
+    #[test]
+    fn ordinary_mail_finds_nothing() {
+        let text = "Hi Dana,\n\nThanks for order 4471-2290 placed 2026-09-14. Invoice INV-2026-00917 \
+            for $12,480.00 is due 10/31/2026; PO 7731902 covers lines 1-14. Tracking \
+            1Z999AA10123456784, parcel 3 of 5, 12.5 kg, box 40x30x20 cm. Meeting moved to \
+            Tuesday 9:30-10:15 in room 2B, building 1177. Ticket #5520318, case 20260914-0042. \
+            Version 2026.9.28.4, build 118822, commit 5a73a118. Serial SN-88213-X. \
+            Ship to 1600 Amphitheatre Pkwy, Mountain View, CA 94043. Revenue grew 18% to \
+            1,204,332 units; see figures 3.1-3.4 and table 12.\n\nBest,\nSam\n\
+            Sam Rivera | +1 (415) 555-2671 | [email protected]";
+        let quiet = ["email-addresses", "phone-numbers"];
+        for detector in all().filter(|d| !quiet.contains(&d.id)) {
+            assert_eq!(
+                detector.count(text),
+                0,
+                "{} fired on ordinary mail",
+                detector.id
+            );
+        }
+    }
+
+    #[test]
+    fn ids_are_unique() {
+        let mut seen = AHashSet::new();
+        for detector in all() {
+            assert!(seen.insert(detector.id), "duplicate id {}", detector.id);
+            assert!(by_id(detector.id).is_some());
+        }
+    }
+}

crates/features/src/mailflow/detectors/templates.rs

@@ -0,0 +1,97 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Templates (§2.3): named sets of detectors, so a policy doesn't pick forty
+//! one at a time. Each is named for what it finds, never for a law, and is a
+//! starting point: once added to a rule, its detectors can be changed.
+
+pub struct Template {
+    pub id: &'static str,
+    pub name: &'static str,
+    pub detectors: &'static [&'static str],
+}
+
+pub static TEMPLATES: &[Template] = &[
+    Template {
+        id: "payment-and-bank",
+        name: "Payment cards and bank accounts",
+        detectors: &["payment-card", "iban", "swift-bic", "us-aba-routing"],
+    },
+    Template {
+        id: "us-personal",
+        name: "US personal identifiers",
+        detectors: &[
+            "us-ssn",
+            "us-itin",
+            "us-ein",
+            "us-drivers-license",
+            "passport",
+            "date-of-birth",
+        ],
+    },
+    Template {
+        id: "uk-personal",
+        name: "UK personal identifiers",
+        detectors: &["uk-nino", "uk-utr", "uk-nhs", "passport", "date-of-birth"],
+    },
+    Template {
+        id: "eu-national",
+        name: "EU national identifiers",
+        detectors: &[
+            "de-tax-id",
+            "de-id-card",
+            "fr-nir",
+            "es-dni-nie",
+            "it-codice-fiscale",
+            "nl-bsn",
+            "be-national-number",
+            "pl-pesel",
+            "se-personnummer",
+            "dk-cpr",
+            "fi-hetu",
+            "ie-pps",
+            "pt-nif",
+            "at-svnr",
+        ],
+    },
+    Template {
+        id: "health",
+        name: "Health identifiers",
+        detectors: &["uk-nhs", "us-mbi", "us-npi", "us-dea", "au-medicare"],
+    },
+    Template {
+        id: "credentials",
+        name: "Credentials and keys",
+        detectors: &["private-key", "credentials"],
+    },
+    Template {
+        id: "contact-lists",
+        name: "Contact lists",
+        detectors: &["email-addresses", "phone-numbers"],
+    },
+];
+
+pub fn by_id(id: &str) -> Option<&'static Template> {
+    TEMPLATES.iter().find(|template| template.id == id)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn every_template_names_real_detectors() {
+        for template in TEMPLATES {
+            for id in template.detectors {
+                assert!(
+                    super::super::by_id(id).is_some(),
+                    "{}: no detector {id}",
+                    template.id
+                );
+            }
+        }
+    }
+}

crates/features/src/mailflow/detectors/uk.rs

@@ -0,0 +1,155 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! United Kingdom identifiers (§2.3): HMRC's National Insurance number and
+//! Unique Taxpayer Reference, and the NHS number.
+
+use super::{Detector, Findings, Region, Strength, word_near};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "uk-nino",
+        "UK National Insurance number",
+        Region::Uk,
+        Strength::Checked,
+        nino,
+    ),
+    Detector::new(
+        "uk-nhs",
+        "UK NHS number",
+        Region::Uk,
+        Strength::Checked,
+        nhs,
+    ),
+    Detector::new(
+        "uk-utr",
+        "UK Unique Taxpayer Reference",
+        Region::Uk,
+        Strength::NeedsWord,
+        utr,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+/// Two letters, six digits (often in pairs), a suffix A–D.
+static NINO: LazyLock<Regex> =
+    LazyLock::new(|| re(r"(?i)\b([A-Z])([A-Z]) ?(\d{2}) ?(\d{2}) ?(\d{2}) ?([A-D])\b"));
+
+/// HMRC's rules: D, F, I, Q, U and V are never used; O never second; and
+/// BG, GB, KN, NK, NT, TN and ZZ are never allocated.
+fn nino_prefix(first: char, second: char) -> bool {
+    const NEVER: &str = "DFIQUV";
+    let pair: String = [first, second].iter().collect();
+    !NEVER.contains(first)
+        && !NEVER.contains(second)
+        && second != 'O'
+        && !["BG", "GB", "KN", "NK", "NT", "TN", "ZZ"].contains(&pair.as_str())
+}
+
+fn nino(text: &str, findings: &mut Findings) {
+    for c in NINO.captures_iter(text) {
+        let first = c[1].to_ascii_uppercase().chars().next().unwrap();
+        let second = c[2].to_ascii_uppercase().chars().next().unwrap();
+        if nino_prefix(first, second) {
+            findings.insert(format!(
+                "{first}{second}{}{}{}{}",
+                &c[3],
+                &c[4],
+                &c[5],
+                c[6].to_ascii_uppercase()
+            ));
+        }
+    }
+}
+
+/// `NNN NNN NNNN` stands alone; ten bare digits need a word.
+static NHS: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{3})([ -]?)(\d{3})([ -]?)(\d{4})\b"));
+
+/// Mod 11: weights 10 down to 2 over the first nine digits; the check digit
+/// is 11 minus the remainder (11 becomes 0; 10 is never issued).
+pub fn nhs_valid(n: &str) -> bool {
+    let d: Vec<u32> = n.bytes().map(|b| u32::from(b - b'0')).collect();
+    let sum: u32 = d[..9].iter().zip((2..=10).rev()).map(|(a, w)| a * w).sum();
+    match 11 - sum % 11 {
+        11 => d[9] == 0,
+        10 => false,
+        check => d[9] == check,
+    }
+}
+
+const NHS_WORDS: &[&str] = &["nhs", "nhs number", "nhs no"];
+
+fn nhs(text: &str, findings: &mut Findings) {
+    for c in NHS.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let n = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        let written = !c[2].is_empty() && c[2] == c[4];
+        if nhs_valid(&n) && (written || word_near(text, whole.start(), whole.end(), NHS_WORDS)) {
+            findings.insert(n);
+        }
+    }
+}
+
+static UTR: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d{5} ?\d{5}\b"));
+
+const UTR_WORDS: &[&str] = &[
+    "utr",
+    "unique taxpayer reference",
+    "tax reference",
+    "self assessment",
+];
+
+fn utr(text: &str, findings: &mut Findings) {
+    for m in UTR.find_iter(text) {
+        if word_near(text, m.start(), m.end(), UTR_WORDS) {
+            findings.insert(m.as_str().replace(' ', ""));
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn national_insurance() {
+        assert_eq!(count("uk-nino", "NI: AB 12 34 56 C, ce123456d"), 2);
+        // Letters never used, pairs never allocated, a suffix past D
+        for bad in [
+            "QQ123456C",
+            "AO123456C",
+            "GB123456A",
+            "AB123456E",
+            "DA123456A",
+        ] {
+            assert_eq!(count("uk-nino", bad), 0, "{bad}");
+        }
+    }
+
+    #[test]
+    fn nhs_numbers() {
+        // The NHS's own example
+        assert_eq!(count("uk-nhs", "943 476 5919"), 1);
+        assert_eq!(count("uk-nhs", "943 476 5918"), 0);
+        assert_eq!(count("uk-nhs", "order 9434765919"), 0);
+        assert_eq!(count("uk-nhs", "NHS number 9434765919"), 1);
+    }
+
+    #[test]
+    fn utr() {
+        assert_eq!(count("uk-utr", "UTR 12345 67890"), 1);
+        assert_eq!(count("uk-utr", "order 1234567890"), 0);
+    }
+}

crates/features/src/mailflow/detectors/us.rs

@@ -0,0 +1,304 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! United States identifiers (§2.3), each from its issuer's published rules:
+//! the SSA (SSN), the IRS (ITIN, EIN), the ABA (routing numbers), CMS (MBI,
+//! NPI) and the DEA.
+
+use super::{Detector, Findings, Region, Strength, checks, digits, stands_alone, word_near};
+use regex::Regex;
+use std::sync::LazyLock;
+
+pub static DETECTORS: &[Detector] = &[
+    Detector::new(
+        "us-ssn",
+        "US Social Security number",
+        Region::Us,
+        Strength::Checked,
+        ssn,
+    ),
+    Detector::new("us-itin", "US ITIN", Region::Us, Strength::Checked, itin),
+    Detector::new("us-ein", "US EIN", Region::Us, Strength::NeedsWord, ein),
+    Detector::new(
+        "us-aba-routing",
+        "US bank routing number",
+        Region::Us,
+        Strength::NeedsWord,
+        aba_routing,
+    ),
+    Detector::new(
+        "us-drivers-license",
+        "US driver's license",
+        Region::Us,
+        Strength::NeedsWord,
+        drivers_license,
+    ),
+    Detector::new(
+        "us-mbi",
+        "US Medicare Beneficiary Identifier",
+        Region::Us,
+        Strength::Checked,
+        mbi,
+    ),
+    Detector::new(
+        "us-npi",
+        "US National Provider Identifier",
+        Region::Us,
+        Strength::NeedsWord,
+        npi,
+    ),
+    Detector::new(
+        "us-dea",
+        "US DEA registration number",
+        Region::Us,
+        Strength::Checked,
+        dea,
+    ),
+];
+
+fn re(pattern: &str) -> Regex {
+    Regex::new(pattern).expect("detector pattern")
+}
+
+/// `AAA-GG-SSSS` (dashes or spaces), or nine bare digits.
+static NINE: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{3})([ -]?)(\d{2})([ -]?)(\d{4})\b"));
+
+/// Numbers the SSA has published as never valid: widely printed examples.
+const SSN_EXAMPLES: &[&str] = &["078051120", "219099999"];
+
+fn ssn_rules(area: u32, group: u32, serial: u32) -> bool {
+    area != 0 && area != 666 && area < 900 && group != 0 && serial != 0
+}
+
+const SSN_WORDS: &[&str] = &["ssn", "social security", "soc sec", "ss#", "ss no"];
+
+fn ssn(text: &str, findings: &mut Findings) {
+    for c in NINE.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let (area, group, serial) = (num(&c[1]), num(&c[3]), num(&c[5]));
+        let number = format!("{}{}{}", &c[1], &c[3], &c[5]);
+        // Written form (with both separators, the same one) stands alone;
+        // nine bare digits need a word
+        let written = !c[2].is_empty() && c[2] == c[4];
+        if ssn_rules(area, group, serial)
+            && !SSN_EXAMPLES.contains(&number.as_str())
+            && (written || word_near(text, whole.start(), whole.end(), SSN_WORDS))
+        {
+            findings.insert(number);
+        }
+    }
+}
+
+/// ITINs: 9XX, then a group in the IRS's ranges.
+fn itin_group(group: u32) -> bool {
+    matches!(group, 50..=65 | 70..=88 | 90..=92 | 94..=99)
+}
+
+const ITIN_WORDS: &[&str] = &["itin", "taxpayer identification", "tax id"];
+
+fn itin(text: &str, findings: &mut Findings) {
+    for c in NINE.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        let written = !c[2].is_empty() && c[2] == c[4];
+        if c[1].starts_with('9')
+            && itin_group(num(&c[3]))
+            && (written || word_near(text, whole.start(), whole.end(), ITIN_WORDS))
+        {
+            findings.insert(format!("{}{}{}", &c[1], &c[3], &c[5]));
+        }
+    }
+}
+
+static EIN: LazyLock<Regex> = LazyLock::new(|| re(r"\b(\d{2})-?(\d{7})\b"));
+
+/// The prefixes the IRS assigns to its campuses and internet EINs.
+fn ein_prefix(prefix: u32) -> bool {
+    matches!(prefix, 1..=6 | 10..=16 | 20..=27 | 30..=48 | 50..=68 | 71..=77 | 80..=88 | 90..=95 | 98 | 99)
+}
+
+const EIN_WORDS: &[&str] = &[
+    "ein",
+    "fein",
+    "employer identification",
+    "tax id",
+    "tin",
+    "federal tax",
+];
+
+fn ein(text: &str, findings: &mut Findings) {
+    for c in EIN.captures_iter(text) {
+        let whole = c.get(0).unwrap();
+        if ein_prefix(num(&c[1])) && word_near(text, whole.start(), whole.end(), EIN_WORDS) {
+            findings.insert(format!("{}{}", &c[1], &c[2]));
+        }
+    }
+}
+
+static ROUTING: LazyLock<Regex> = LazyLock::new(|| re(r"\b\d{9}\b"));
+
+/// The ABA check: 3, 7 and 1 weights, mod 10; and a Federal Reserve prefix.
+pub fn aba_valid(n: &str) -> bool {
+    let d: Vec<u32> = n.bytes().map(|b| u32::from(b - b'0')).collect();
+    let prefix = d[0] * 10 + d[1];
+    matches!(prefix, 0..=12 | 21..=32 | 61..=72 | 80)
+        && (3 * (d[0] + d[3] + d[6]) + 7 * (d[1] + d[4] + d[7]) + (d[2] + d[5] + d[8]))
+            .is_multiple_of(10)
+}
+
+const ROUTING_WORDS: &[&str] = &["routing", "aba", "rtn", "routing number", "transit"];
+
+fn aba_routing(text: &str, findings: &mut Findings) {
+    for m in ROUTING.find_iter(text) {
+        // One random number in ten passes the check: always needs a word
+        if aba_valid(m.as_str()) && word_near(text, m.start(), m.end(), ROUTING_WORDS) {
+            findings.insert(m.as_str());
+        }
+    }
+}
+
+/// The shapes states issue: up to two letters, then 5–14 digits, dashes
+/// allowed (Florida and Illinois print them).
+static LICENSE: LazyLock<Regex> = LazyLock::new(|| re(r"\b[A-Z]{0,2}\d[\d-]{3,16}\d\b"));
+
+const LICENSE_WORDS: &[&str] = &[
+    "driver's license",
+    "drivers license",
+    "driver license",
+    "driver's licence",
+    "dl",
+    "dl#",
+    "license number",
+    "lic no",
+    "dmv",
+];
+
+fn drivers_license(text: &str, findings: &mut Findings) {
+    for m in LICENSE.find_iter(text) {
+        let n = digits(m.as_str());
+        if (5..=14).contains(&n.len()) && word_near(text, m.start(), m.end(), LICENSE_WORDS) {
+            findings.insert(m.as_str().replace('-', ""));
+        }
+    }
+}
+
+/// CMS's MBI: 11 characters in a fixed pattern of digits, letters and
+/// either, the letters S, L, O, I, B and Z never used; dashes may follow the
+/// 4th and 7th.
+static MBI: LazyLock<Regex> = LazyLock::new(|| {
+    let c = "[AC-HJKMNP-RT-Y]";
+    let an = "[AC-HJKMNP-RT-Y0-9]";
+    re(&format!(
+        r"\b[1-9]{c}{an}[0-9]-?{c}{an}[0-9]-?{c}{c}[0-9][0-9]\b"
+    ))
+});
+
+fn mbi(text: &str, findings: &mut Findings) {
+    for m in MBI.find_iter(text) {
+        findings.insert(m.as_str().replace('-', ""));
+    }
+}
+
+static TEN: LazyLock<Regex> = LazyLock::new(|| re(r"\b[12]\d{9}\b"));
+
+const NPI_WORDS: &[&str] = &["npi", "national provider", "provider id", "provider number"];
+
+/// NPI: Luhn over the ISO card-issuer prefix 80840 and the number.
+fn npi(text: &str, findings: &mut Findings) {
+    for m in TEN.find_iter(text) {
+        if checks::luhn(&format!("80840{}", m.as_str()))
+            && word_near(text, m.start(), m.end(), NPI_WORDS)
+        {
+            findings.insert(m.as_str());
+        }
+    }
+}
+
+static DEA: LazyLock<Regex> = LazyLock::new(|| re(r"\b([ABCDEFGHJKLMPRSTUX][A-Z9])(\d{7})\b"));
+
+/// DEA: (1st + 3rd + 5th) + 2 × (2nd + 4th + 6th) ends in the 7th digit.
+fn dea(text: &str, findings: &mut Findings) {
+    for c in DEA.captures_iter(text) {
+        let d: Vec<u32> = c[2].bytes().map(|b| u32::from(b - b'0')).collect();
+        if ((d[0] + d[2] + d[4]) + 2 * (d[1] + d[3] + d[5])) % 10 == d[6] {
+            let whole = c.get(0).unwrap();
+            if stands_alone(text, whole.start(), whole.end()) {
+                findings.insert(whole.as_str());
+            }
+        }
+    }
+}
+
+fn num(s: &str) -> u32 {
+    s.parse().unwrap_or(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mailflow::detectors::by_id;
+
+    fn count(id: &str, text: &str) -> usize {
+        by_id(id).unwrap().count(text)
+    }
+
+    #[test]
+    fn ssn() {
+        assert_eq!(count("us-ssn", "SSN 536-22-1234, also 536 22 1235"), 2);
+        // Bare digits: only with a word
+        assert_eq!(count("us-ssn", "ref 536221234"), 0);
+        assert_eq!(count("us-ssn", "social security: 536221234"), 1);
+        // Never issued, the SSA's printed examples, mixed separators
+        for bad in [
+            "000-12-3456",
+            "666-12-3456",
+            "912-12-3456",
+            "123-00-4567",
+            "123-45-0000",
+            "078-05-1120",
+            "536-22 1234",
+        ] {
+            assert_eq!(count("us-ssn", bad), 0, "{bad}");
+        }
+    }
+
+    #[test]
+    fn itin_and_ein() {
+        assert_eq!(count("us-itin", "912-70-1234"), 1);
+        assert_eq!(count("us-itin", "912-69-1234"), 0);
+        assert_eq!(count("us-ssn", "912-70-1234"), 0);
+        assert_eq!(count("us-ein", "EIN: 12-3456789"), 1);
+        assert_eq!(count("us-ein", "part 12-3456789"), 0);
+        assert_eq!(count("us-ein", "EIN 07-3456789"), 0);
+    }
+
+    #[test]
+    fn routing_needs_a_word() {
+        assert_eq!(count("us-aba-routing", "Routing number 011000015"), 1);
+        assert_eq!(count("us-aba-routing", "ABA 021000021"), 1);
+        assert_eq!(count("us-aba-routing", "invoice 011000015"), 0);
+        assert_eq!(count("us-aba-routing", "routing 011000016"), 0);
+    }
+
+    #[test]
+    fn licenses() {
+        assert_eq!(count("us-drivers-license", "Driver's license: D1234567"), 1);
+        assert_eq!(count("us-drivers-license", "DL# S123-456-78-901-0"), 1);
+        assert_eq!(count("us-drivers-license", "Order D1234567"), 0);
+    }
+
+    #[test]
+    fn health_identifiers() {
+        // CMS's own MBI example
+        assert_eq!(count("us-mbi", "Medicare 1EG4-TE5-MK73"), 1);
+        assert_eq!(count("us-mbi", "1EG4TE5MK73"), 1);
+        assert_eq!(count("us-mbi", "1EG4-TE5-MK7S"), 0);
+        // CMS's NPI example
+        assert_eq!(count("us-npi", "NPI 1234567893"), 1);
+        assert_eq!(count("us-npi", "NPI 1234567894"), 0);
+        assert_eq!(count("us-npi", "call 1234567893"), 0);
+        assert_eq!(count("us-dea", "DEA AB1234563"), 1);
+        assert_eq!(count("us-dea", "AB1234564"), 0);
+    }
+}

crates/features/src/mailflow/engine.rs

@@ -0,0 +1,695 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Evaluating rules against a message (§2.1–§2.4). Rules are compiled once,
+//! when they change: word lists become automata, patterns regexes. A message
+//! is then checked against every enabled rule in order; each detector runs
+//! at most once per message, and only when some rule asks for it.
+//!
+//! Pure: the caller parses the message, extracts attachment text
+//! ([`super::extract`]) and knows the sender's groups and tenant. What comes
+//! back is which rules matched, with each detector's count, and what DLP
+//! decided; the matched text itself never leaves here (§2.7).
+
+use super::{
+    detectors::{self, Findings},
+    extract::Extracted,
+    rules::{Action, Condition, Direction, Kind, Rule},
+    words::{Pattern, WordList},
+};
+use ahash::AHashMap;
+use std::borrow::Cow;
+
+/// Who sent a message, and to whom.
+#[derive(Debug, Clone, Default)]
+pub struct Envelope<'a> {
+    /// Outgoing (an authenticated sender) or incoming.
+    pub outgoing: bool,
+    pub sender: &'a str,
+    pub sender_groups: &'a [u32],
+    pub sender_tenant: Option<u32>,
+    pub recipients: Vec<Recipient<'a>>,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct Recipient<'a> {
+    pub address: &'a str,
+    /// At a domain this server hosts.
+    pub local: bool,
+    pub groups: &'a [u32],
+}
+
+#[derive(Debug, Clone)]
+pub struct Attachment<'a> {
+    pub name: Option<&'a str>,
+    /// Declared type, or detected where the caller knows better.
+    pub content_type: &'a str,
+    pub size: u64,
+    pub extracted: Extracted,
+}
+
+/// What rules look at.
+#[derive(Debug, Clone, Default)]
+pub struct Content<'a> {
+    pub subject: &'a str,
+    /// Each text and HTML part, as text.
+    pub bodies: Vec<Cow<'a, str>>,
+    pub headers: Vec<(&'a str, &'a str)>,
+    pub attachments: Vec<Attachment<'a>>,
+    pub size: u64,
+    /// Text past the inspection limit wasn't read.
+    pub truncated: bool,
+}
+
+impl Content<'_> {
+    fn texts(&self) -> impl Iterator<Item = &str> {
+        std::iter::once(self.subject)
+            .chain(self.bodies.iter().map(|b| b.as_ref()))
+            .chain(self.attachments.iter().filter_map(|a| match &a.extracted {
+                Extracted::Text(text) => Some(text.as_str()),
+                _ => None,
+            }))
+    }
+
+    fn cant_be_inspected(&self) -> bool {
+        self.truncated
+            || self
+                .attachments
+                .iter()
+                .any(|a| matches!(a.extracted, Extracted::NotInspectable(_)))
+    }
+}
+
+enum Check {
+    Plain(Condition),
+    Words(WordList, u32),
+    Pattern(Pattern, u32),
+    Header {
+        name: String,
+        contains: Option<String>,
+        matches: Option<Pattern>,
+    },
+    AttachmentName(Pattern),
+}
+
+struct CompiledRule {
+    rule: Rule,
+    conditions: Vec<Check>,
+    exceptions: Vec<Check>,
+}
+
+/// The enabled rules, ready to run.
+pub struct Compiled {
+    rules: Vec<CompiledRule>,
+}
+
+/// A rule reference, for notices and the audit record.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct RuleRef {
+    pub id: u32,
+    pub name: String,
+    pub notice: String,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Match {
+    pub rule_id: u32,
+    pub name: String,
+    pub kind: Kind,
+    pub actions: Vec<Action>,
+    /// Each detector (or `words`, `pattern`) that counted, and its count.
+    pub counts: Vec<(String, usize)>,
+}
+
+#[derive(Debug, Default)]
+pub struct Outcome {
+    pub matched: Vec<Match>,
+    pub blocks: Vec<RuleRef>,
+    pub holds: Vec<(RuleRef, bool)>,
+    pub warns: Vec<RuleRef>,
+}
+
+/// What DLP decided, strictest first (§2.4).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Decision {
+    Pass,
+    Block(Vec<RuleRef>),
+    Hold {
+        rules: Vec<RuleRef>,
+        notify_sender: bool,
+    },
+    Warn(Vec<RuleRef>),
+}
+
+impl Outcome {
+    /// Block beats hold beats warn. An override (§2.5) answers the warnings
+    /// only: a block or hold still applies.
+    pub fn decision(&self, overridden: bool) -> Decision {
+        if !self.blocks.is_empty() {
+            Decision::Block(self.blocks.clone())
+        } else if !self.holds.is_empty() {
+            Decision::Hold {
+                rules: self.holds.iter().map(|(r, _)| r.clone()).collect(),
+                notify_sender: self.holds.iter().any(|(_, notify)| *notify),
+            }
+        } else if !self.warns.is_empty() && !overridden {
+            Decision::Warn(self.warns.clone())
+        } else {
+            Decision::Pass
+        }
+    }
+}
+
+fn compile_check(condition: &Condition) -> Result<Check, String> {
+    Ok(match condition {
+        Condition::Words { words, at_least } => Check::Words(WordList::new(words)?, *at_least),
+        Condition::Pattern { pattern, at_least } => {
+            Check::Pattern(Pattern::new(pattern)?, *at_least)
+        }
+        Condition::Header {
+            name,
+            contains,
+            matches,
+        } => Check::Header {
+            name: name.to_ascii_lowercase(),
+            contains: contains.as_ref().map(|c| c.to_lowercase()),
+            matches: matches.as_deref().map(Pattern::new).transpose()?,
+        },
+        Condition::AttachmentName { pattern } => Check::AttachmentName(Pattern::new(pattern)?),
+        other => Check::Plain(other.clone()),
+    })
+}
+
+impl Compiled {
+    /// Compiles the enabled rules; one that no longer compiles (a detector
+    /// renamed since it was saved) is skipped and named in the second list.
+    pub fn new(rules: &[Rule]) -> (Self, Vec<(u32, String)>) {
+        let mut compiled = Vec::new();
+        let mut skipped = Vec::new();
+        for rule in rules.iter().filter(|r| r.enabled) {
+            let result = rule.validate().map_err(|e| e.reason).and_then(|_| {
+                Ok(CompiledRule {
+                    rule: rule.clone(),
+                    conditions: rule
+                        .conditions
+                        .iter()
+                        .map(compile_check)
+                        .collect::<Result<_, _>>()?,
+                    exceptions: rule
+                        .exceptions
+                        .iter()
+                        .map(compile_check)
+                        .collect::<Result<_, _>>()?,
+                })
+            });
+            match result {
+                Ok(c) => compiled.push(c),
+                Err(reason) => skipped.push((rule.id, reason)),
+            }
+        }
+        compiled.sort_by_key(|c| (c.rule.priority, c.rule.id));
+        (Self { rules: compiled }, skipped)
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.rules.is_empty()
+    }
+
+    /// Whether any rule could apply to mail going this way, so a caller can
+    /// skip parsing when none can.
+    pub fn applies_to(&self, outgoing: bool) -> bool {
+        self.rules
+            .iter()
+            .any(|c| direction_matches(c.rule.direction, outgoing))
+    }
+
+    pub fn evaluate(&self, envelope: &Envelope<'_>, content: &Content<'_>) -> Outcome {
+        let mut state = State {
+            content,
+            detected: AHashMap::new(),
+        };
+        let mut outcome = Outcome::default();
+        for compiled in &self.rules {
+            let rule = &compiled.rule;
+            if !direction_matches(rule.direction, envelope.outgoing) {
+                continue;
+            }
+            let mut counts = Vec::new();
+            let all_match = compiled
+                .conditions
+                .iter()
+                .all(|check| state.check(check, envelope, &mut counts));
+            if !all_match {
+                continue;
+            }
+            let mut ignored = Vec::new();
+            if compiled
+                .exceptions
+                .iter()
+                .any(|check| state.check(check, envelope, &mut ignored))
+            {
+                continue;
+            }
+            for action in &rule.actions {
+                let reference = |notice: &str| RuleRef {
+                    id: rule.id,
+                    name: rule.name.clone(),
+                    notice: notice.to_string(),
+                };
+                match action {
+                    Action::Block { notice } => outcome.blocks.push(reference(notice)),
+                    Action::Hold {
+                        notice,
+                        notify_sender,
+                    } => outcome.holds.push((reference(notice), *notify_sender)),
+                    Action::Warn { notice } => outcome.warns.push(reference(notice)),
+                    _ => {}
+                }
+            }
+            outcome.matched.push(Match {
+                rule_id: rule.id,
+                name: rule.name.clone(),
+                kind: rule.kind,
+                actions: rule.actions.clone(),
+                counts,
+            });
+            if rule.stop_processing {
+                break;
+            }
+        }
+        outcome
+    }
+}
+
+fn direction_matches(direction: Direction, outgoing: bool) -> bool {
+    match direction {
+        Direction::Any => true,
+        Direction::Outgoing => outgoing,
+        Direction::Incoming => !outgoing,
+    }
+}
+
+fn domain_of(address: &str) -> &str {
+    address.rsplit_once('@').map_or("", |(_, d)| d)
+}
+
+fn in_list(value: &str, list: &[String]) -> bool {
+    list.iter().any(|v| v.eq_ignore_ascii_case(value))
+}
+
+struct State<'c, 'a> {
+    content: &'c Content<'a>,
+    /// Each detector's count, run once per message.
+    detected: AHashMap<&'static str, usize>,
+}
+
+impl State<'_, '_> {
+    fn detector_count(&mut self, id: &str) -> usize {
+        let Some(detector) = detectors::by_id(id) else {
+            return 0;
+        };
+        if let Some(count) = self.detected.get(detector.id) {
+            return *count;
+        }
+        let mut findings = Findings::default();
+        for text in self.content.texts() {
+            detector.find(text, &mut findings);
+        }
+        self.detected.insert(detector.id, findings.len());
+        findings.len()
+    }
+
+    fn check(
+        &mut self,
+        check: &Check,
+        envelope: &Envelope<'_>,
+        counts: &mut Vec<(String, usize)>,
+    ) -> bool {
+        let content = self.content;
+        match check {
+            Check::Words(list, at_least) => {
+                let n: usize = content.texts().map(|t| list.count(t)).sum();
+                counts.push(("words".into(), n));
+                n >= *at_least as usize
+            }
+            Check::Pattern(pattern, at_least) => {
+                let n: usize = content.texts().map(|t| pattern.count(t)).sum();
+                counts.push(("pattern".into(), n));
+                n >= *at_least as usize
+            }
+            Check::Header {
+                name,
+                contains,
+                matches,
+            } => content
+                .headers
+                .iter()
+                .filter(|(n, _)| n.eq_ignore_ascii_case(name))
+                .any(|(_, value)| match (contains, matches) {
+                    (Some(needle), _) => value.to_lowercase().contains(needle.as_str()),
+                    (_, Some(pattern)) => pattern.count(value) > 0,
+                    _ => true,
+                }),
+            Check::AttachmentName(pattern) => content
+                .attachments
+                .iter()
+                .any(|a| a.name.is_some_and(|n| pattern.count(n) > 0)),
+            Check::Plain(condition) => match condition {
+                Condition::SenderAddress { addresses } => in_list(envelope.sender, addresses),
+                Condition::SenderDomain { domains } => in_list(domain_of(envelope.sender), domains),
+                Condition::SenderGroup { groups } => {
+                    envelope.sender_groups.iter().any(|g| groups.contains(g))
+                }
+                Condition::SenderTenant { tenants } => {
+                    envelope.sender_tenant.is_some_and(|t| tenants.contains(&t))
+                }
+                Condition::RecipientAddress { addresses } => envelope
+                    .recipients
+                    .iter()
+                    .any(|r| in_list(r.address, addresses)),
+                Condition::RecipientDomain { domains } => envelope
+                    .recipients
+                    .iter()
+                    .any(|r| in_list(domain_of(r.address), domains)),
+                Condition::RecipientGroup { groups } => envelope
+                    .recipients
+                    .iter()
+                    .any(|r| r.groups.iter().any(|g| groups.contains(g))),
+                Condition::RecipientOutside => envelope.recipients.iter().any(|r| !r.local),
+                Condition::AttachmentType { types } => content.attachments.iter().any(|a| {
+                    let ct = a.content_type.to_ascii_lowercase();
+                    types
+                        .iter()
+                        .any(|t| ct.starts_with(&t.to_ascii_lowercase()))
+                }),
+                Condition::AttachmentExtension { extensions } => {
+                    content.attachments.iter().any(|a| {
+                        a.name
+                            .and_then(|n| n.rsplit_once('.'))
+                            .is_some_and(|(_, ext)| {
+                                extensions
+                                    .iter()
+                                    .any(|e| e.trim_start_matches('.').eq_ignore_ascii_case(ext))
+                            })
+                    })
+                }
+                Condition::AttachmentSizeOver { bytes } => {
+                    content.attachments.iter().any(|a| a.size > *bytes)
+                }
+                Condition::AttachmentCountOver { count } => {
+                    content.attachments.len() > *count as usize
+                }
+                Condition::CantBeInspected => content.cant_be_inspected(),
+                Condition::MessageSizeOver { bytes } => content.size > *bytes,
+                Condition::Detected { detectors } => {
+                    let mut any = false;
+                    for d in detectors {
+                        let n = self.detector_count(&d.id);
+                        counts.push((d.id.clone(), n));
+                        any |= n >= d.at_least as usize;
+                    }
+                    any
+                }
+                // Compiled into their own checks
+                Condition::Words { .. }
+                | Condition::Pattern { .. }
+                | Condition::Header { .. }
+                | Condition::AttachmentName { .. } => false,
+            },
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::mailflow::{
+        extract::Why,
+        rules::{DetectorMin, Position},
+    };
+
+    fn rule(id: u32, kind: Kind, conditions: Vec<Condition>, action: Action) -> Rule {
+        Rule {
+            id,
+            name: format!("rule {id}"),
+            description: String::new(),
+            kind,
+            enabled: true,
+            priority: id as i32,
+            direction: if kind == Kind::Dlp {
+                Direction::Outgoing
+            } else {
+                Direction::Any
+            },
+            conditions,
+            exceptions: vec![],
+            actions: vec![action],
+            stop_processing: false,
+            created_by: String::new(),
+            created_at: 0,
+            updated_at: 0,
+        }
+    }
+
+    fn envelope(outside: bool) -> Envelope<'static> {
+        Envelope {
+            outgoing: true,
+            sender: "[email protected]",
+            sender_groups: &[7],
+            sender_tenant: None,
+            recipients: vec![Recipient {
+                address: if outside {
+                    "[email protected]"
+                } else {
+                    "[email protected]"
+                },
+                local: !outside,
+                groups: &[],
+            }],
+        }
+    }
+
+    fn cards(n: usize) -> Content<'static> {
+        let body: String = [
+            "4242 4242 4242 4242",
+            "5555-5555-5555-4444",
+            "378282246310005",
+            "6011111111111117",
+            "3566002020360505",
+        ]
+        .iter()
+        .take(n)
+        .map(|c| format!("card {c}\n"))
+        .collect();
+        Content {
+            subject: "Numbers",
+            bodies: vec![body.into()],
+            ..Default::default()
+        }
+    }
+
+    fn five_cards_outside(action: Action) -> Rule {
+        rule(
+            1,
+            Kind::Dlp,
+            vec![
+                Condition::RecipientOutside,
+                Condition::Detected {
+                    detectors: vec![DetectorMin {
+                        id: "payment-card".into(),
+                        at_least: 5,
+                    }],
+                },
+            ],
+            action,
+        )
+    }
+
+    #[test]
+    fn detector_threshold_and_recipients() {
+        let (rules, skipped) = Compiled::new(&[five_cards_outside(Action::Hold {
+            notice: "Held".into(),
+            notify_sender: true,
+        })]);
+        assert!(skipped.is_empty());
+        let outcome = rules.evaluate(&envelope(true), &cards(5));
+        assert_eq!(
+            outcome.matched[0].counts,
+            vec![("payment-card".to_string(), 5)]
+        );
+        assert!(matches!(
+            outcome.decision(false),
+            Decision::Hold {
+                notify_sender: true,
+                ..
+            }
+        ));
+        // Four cards, or everyone inside: nothing
+        assert_eq!(
+            rules.evaluate(&envelope(true), &cards(4)).decision(false),
+            Decision::Pass
+        );
+        assert_eq!(
+            rules.evaluate(&envelope(false), &cards(5)).decision(false),
+            Decision::Pass
+        );
+    }
+
+    #[test]
+    fn strictest_wins_and_override_answers_warnings_only() {
+        let warn = five_cards_outside(Action::Warn {
+            notice: "Sure?".into(),
+        });
+        let mut block = five_cards_outside(Action::Block {
+            notice: "No".into(),
+        });
+        block.id = 2;
+        let (rules, _) = Compiled::new(&[warn.clone(), block]);
+        let outcome = rules.evaluate(&envelope(true), &cards(5));
+        assert!(matches!(outcome.decision(true), Decision::Block(_)));
+        let (rules, _) = Compiled::new(&[warn]);
+        let outcome = rules.evaluate(&envelope(true), &cards(5));
+        assert!(matches!(outcome.decision(false), Decision::Warn(ref w) if w[0].notice == "Sure?"));
+        assert_eq!(outcome.decision(true), Decision::Pass);
+    }
+
+    #[test]
+    fn exceptions_order_and_stop_processing() {
+        let disclaimer = |id| {
+            rule(
+                id,
+                Kind::Transport,
+                vec![Condition::RecipientOutside],
+                Action::AddDisclaimer {
+                    text: "t".into(),
+                    html: None,
+                    position: Position::Bottom,
+                },
+            )
+        };
+        let mut first = disclaimer(1);
+        first.stop_processing = true;
+        let (rules, _) = Compiled::new(&[disclaimer(2), first.clone()]);
+        let outcome = rules.evaluate(&envelope(true), &cards(0));
+        assert_eq!(
+            outcome
+                .matched
+                .iter()
+                .map(|m| m.rule_id)
+                .collect::<Vec<_>>(),
+            vec![1]
+        );
+
+        first.stop_processing = false;
+        first.exceptions = vec![Condition::SenderGroup { groups: vec![7] }];
+        let (rules, _) = Compiled::new(&[disclaimer(2), first]);
+        let outcome = rules.evaluate(&envelope(true), &cards(0));
+        assert_eq!(
+            outcome
+                .matched
+                .iter()
+                .map(|m| m.rule_id)
+                .collect::<Vec<_>>(),
+            vec![2]
+        );
+    }
+
+    #[test]
+    fn content_conditions() {
+        let content = Content {
+            subject: "Project Falcon",
+            bodies: vec!["see attached".into()],
+            headers: vec![("X-Class", "Internal only")],
+            attachments: vec![
+                Attachment {
+                    name: Some("plan.docx"),
+                    content_type: "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+                    size: 40_000,
+                    extracted: Extracted::Text("IBAN GB29 NWBK 6016 1331 9268 19".into()),
+                },
+                Attachment {
+                    name: Some("scan.pdf"),
+                    content_type: "application/pdf",
+                    size: 900_000,
+                    extracted: Extracted::NotInspectable(Why::Pdf),
+                },
+            ],
+            size: 1_000_000,
+            truncated: false,
+        };
+        let block = || Action::Block { notice: "n".into() };
+        let checks = [
+            (
+                Condition::Words {
+                    words: vec!["project falcon".into()],
+                    at_least: 1,
+                },
+                true,
+            ),
+            (
+                Condition::Header {
+                    name: "x-class".into(),
+                    contains: Some("internal".into()),
+                    matches: None,
+                },
+                true,
+            ),
+            (
+                Condition::AttachmentExtension {
+                    extensions: vec![".PDF".into()],
+                },
+                true,
+            ),
+            (
+                Condition::AttachmentType {
+                    types: vec!["image/".into()],
+                },
+                false,
+            ),
+            (Condition::AttachmentSizeOver { bytes: 500_000 }, true),
+            (Condition::AttachmentCountOver { count: 2 }, false),
+            (Condition::CantBeInspected, true),
+            (Condition::MessageSizeOver { bytes: 2_000_000 }, false),
+            (
+                Condition::Detected {
+                    detectors: vec![DetectorMin {
+                        id: "iban".into(),
+                        at_least: 1,
+                    }],
+                },
+                true,
+            ),
+            (
+                Condition::SenderDomain {
+                    domains: vec!["EXAMPLE.com".into()],
+                },
+                true,
+            ),
+        ];
+        for (condition, expected) in checks {
+            let (rules, skipped) =
+                Compiled::new(&[rule(1, Kind::Dlp, vec![condition.clone()], block())]);
+            assert!(skipped.is_empty(), "{condition:?}");
+            let matched = !rules.evaluate(&envelope(true), &content).matched.is_empty();
+            assert_eq!(matched, expected, "{condition:?}");
+        }
+    }
+
+    #[test]
+    fn direction_and_disabled_rules() {
+        let mut r = five_cards_outside(Action::Block { notice: "n".into() });
+        let (rules, _) = Compiled::new(std::slice::from_ref(&r));
+        assert!(rules.applies_to(true) && !rules.applies_to(false));
+        let mut incoming = envelope(true);
+        incoming.outgoing = false;
+        assert_eq!(
+            rules.evaluate(&incoming, &cards(5)).decision(false),
+            Decision::Pass
+        );
+        r.enabled = false;
+        assert!(Compiled::new(&[r]).0.is_empty());
+    }
+}

crates/features/src/mailflow/extract.rs

@@ -0,0 +1,694 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! The text of an attachment, for the detectors (§2.3), or why there isn't
+//! one.
+//!
+//! Read: text files (plain, CSV, JSON, XML, HTML), Office Open XML (DOCX,
+//! XLSX, PPTX) and OpenDocument (ODT, ODS, ODP) documents, and ZIP archives
+//! one level deep. **Can't be inspected**: encrypted or password-protected
+//! files, PDF (settled answer 2), the older binary Office formats, archives
+//! inside archives, and anything past the limits. Everything else (images,
+//! audio, programs) has no text to read and is neither.
+//!
+//! Office files are ZIP archives of XML, read here with the `zip` and
+//! `quick-xml` crates the server already uses: no outside converter runs.
+
+use quick_xml::{Reader, XmlVersion, events::Event};
+use std::io::{Cursor, Read};
+
+/// How much may be unpacked from one attachment, and from how many entries.
+#[derive(Debug, Clone, Copy)]
+pub struct Limits {
+    pub max_unpacked: u64,
+    pub max_entries: usize,
+}
+
+impl Default for Limits {
+    fn default() -> Self {
+        Self {
+            max_unpacked: 50 * 1024 * 1024,
+            max_entries: 10_000,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Extracted {
+    /// The text to check.
+    Text(String),
+    /// A kind of file with no text in it: nothing to check, nothing missed.
+    NoText,
+    /// A file that may hold text the detectors couldn't read.
+    NotInspectable(Why),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Why {
+    Encrypted,
+    Pdf,
+    LegacyOffice,
+    NestedArchive,
+    TooLarge,
+    Damaged,
+}
+
+impl Why {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            Why::Encrypted => "encrypted",
+            Why::Pdf => "pdf",
+            Why::LegacyOffice => "legacy-office",
+            Why::NestedArchive => "nested-archive",
+            Why::TooLarge => "too-large",
+            Why::Damaged => "damaged",
+        }
+    }
+}
+
+const OLE_MAGIC: &[u8] = &[0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1];
+const ZIP_MAGIC: &[u8] = b"PK\x03\x04";
+
+/// What an attachment says, from its declared type, its file name and, above
+/// all, its first bytes.
+pub fn extract(
+    content_type: &str,
+    file_name: Option<&str>,
+    data: &[u8],
+    limits: &Limits,
+) -> Extracted {
+    extract_at(content_type, file_name, data, limits, 0)
+}
+
+fn extract_at(
+    content_type: &str,
+    file_name: Option<&str>,
+    data: &[u8],
+    limits: &Limits,
+    depth: u8,
+) -> Extracted {
+    let content_type = content_type.to_ascii_lowercase();
+    let extension = file_name
+        .and_then(|name| name.rsplit_once('.'))
+        .map(|(_, ext)| ext.to_ascii_lowercase())
+        .unwrap_or_default();
+
+    if data.len() as u64 > limits.max_unpacked {
+        return Extracted::NotInspectable(Why::TooLarge);
+    }
+    if data.starts_with(b"%PDF-") || content_type == "application/pdf" || extension == "pdf" {
+        return Extracted::NotInspectable(Why::Pdf);
+    }
+    if data.starts_with(OLE_MAGIC) {
+        // An encrypted OOXML file is an OLE container holding the encrypted
+        // package; any other OLE file is a legacy .doc, .xls or .ppt
+        return Extracted::NotInspectable(if has_utf16(data, "EncryptedPackage") {
+            Why::Encrypted
+        } else {
+            Why::LegacyOffice
+        });
+    }
+    if data.starts_with(ZIP_MAGIC) {
+        if depth > 0 {
+            return Extracted::NotInspectable(Why::NestedArchive);
+        }
+        return zip(data, limits);
+    }
+    if is_text(&content_type, &extension) {
+        let text = decode_text(data);
+        return Extracted::Text(
+            if content_type == "text/html" || matches!(extension.as_str(), "html" | "htm") {
+                strip_html(&text)
+            } else {
+                text
+            },
+        );
+    }
+    Extracted::NoText
+}
+
+fn is_text(content_type: &str, extension: &str) -> bool {
+    content_type.starts_with("text/")
+        || matches!(
+            content_type,
+            "application/json"
+                | "application/xml"
+                | "application/csv"
+                | "application/x-csv"
+                | "message/rfc822"
+        )
+        || matches!(
+            extension,
+            "txt"
+                | "csv"
+                | "tsv"
+                | "json"
+                | "xml"
+                | "md"
+                | "log"
+                | "html"
+                | "htm"
+                | "eml"
+                | "ics"
+                | "vcf"
+        )
+}
+
+/// UTF-16 with a byte order mark, else UTF-8 (lossy).
+fn decode_text(data: &[u8]) -> String {
+    let utf16 = |bytes: &[u8], big: bool| {
+        let units: Vec<u16> = bytes
+            .as_chunks::<2>()
+            .0
+            .iter()
+            .map(|&c| {
+                if big {
+                    u16::from_be_bytes(c)
+                } else {
+                    u16::from_le_bytes(c)
+                }
+            })
+            .collect();
+        String::from_utf16_lossy(&units)
+    };
+    match data {
+        [0xFF, 0xFE, rest @ ..] => utf16(rest, false),
+        [0xFE, 0xFF, rest @ ..] => utf16(rest, true),
+        [0xEF, 0xBB, 0xBF, rest @ ..] => String::from_utf8_lossy(rest).into_owned(),
+        _ => String::from_utf8_lossy(data).into_owned(),
+    }
+}
+
+fn has_utf16(data: &[u8], needle: &str) -> bool {
+    let needle: Vec<u8> = needle.encode_utf16().flat_map(u16::to_le_bytes).collect();
+    data.windows(needle.len()).any(|w| w == needle.as_slice())
+}
+
+/// Tags out, the common entities decoded, block ends as new lines.
+fn strip_html(html: &str) -> String {
+    let mut out = String::with_capacity(html.len());
+    let mut in_tag = false;
+    let mut skip_until: Option<&str> = None;
+    let lower = html.to_ascii_lowercase();
+    let mut i = 0;
+    let bytes = html.as_bytes();
+    while i < bytes.len() {
+        if let Some(end) = skip_until {
+            match lower[i..].find(end) {
+                Some(at) => {
+                    i += at + end.len();
+                    skip_until = None;
+                }
+                None => break,
+            }
+            continue;
+        }
+        let c = bytes[i];
+        if in_tag {
+            if c == b'>' {
+                in_tag = false;
+            }
+            i += 1;
+            continue;
+        }
+        if c == b'<' {
+            if lower[i..].starts_with("<script") {
+                skip_until = Some("</script>");
+            } else if lower[i..].starts_with("<style") {
+                skip_until = Some("</style>");
+            } else {
+                if [
+                    "<br", "<p", "</p", "<div", "</div", "<tr", "<li", "<td", "<th",
+                ]
+                .iter()
+                .any(|t| lower[i..].starts_with(t))
+                {
+                    out.push(
+                        if lower[i..].starts_with("<td") || lower[i..].starts_with("<th") {
+                            '\t'
+                        } else {
+                            '\n'
+                        },
+                    );
+                }
+                in_tag = true;
+            }
+            i += 1;
+            continue;
+        }
+        // Copy up to the next tag
+        let next = html[i..].find('<').map_or(html.len(), |at| i + at);
+        out.push_str(&html[i..next]);
+        i = next;
+    }
+    for (entity, text) in [
+        ("&nbsp;", " "),
+        ("&lt;", "<"),
+        ("&gt;", ">"),
+        ("&quot;", "\""),
+        ("&#39;", "'"),
+        ("&amp;", "&"),
+    ] {
+        out = out.replace(entity, text);
+    }
+    out
+}
+
+/// A ZIP file: an Office document, an OpenDocument, or an archive.
+fn zip(data: &[u8], limits: &Limits) -> Extracted {
+    let Ok(mut archive) = zip::ZipArchive::new(Cursor::new(data)) else {
+        return Extracted::NotInspectable(Why::Damaged);
+    };
+    if archive.len() > limits.max_entries {
+        return Extracted::NotInspectable(Why::TooLarge);
+    }
+    let mut names = Vec::with_capacity(archive.len());
+    let mut declared: u64 = 0;
+    for i in 0..archive.len() {
+        let Ok(entry) = archive.by_index_raw(i) else {
+            return Extracted::NotInspectable(Why::Damaged);
+        };
+        if entry.encrypted() {
+            return Extracted::NotInspectable(Why::Encrypted);
+        }
+        declared = declared.saturating_add(entry.size());
+        names.push(entry.name().to_string());
+    }
+    if declared > limits.max_unpacked {
+        return Extracted::NotInspectable(Why::TooLarge);
+    }
+    let mut budget = limits.max_unpacked;
+    let mut read =
+        |archive: &mut zip::ZipArchive<Cursor<&[u8]>>, name: &str| -> Result<Vec<u8>, Why> {
+            let entry = archive.by_name(name).map_err(|_| Why::Damaged)?;
+            let mut bytes = Vec::new();
+            // Declared sizes can lie: stop at the budget whatever they say
+            entry
+                .take(budget + 1)
+                .read_to_end(&mut bytes)
+                .map_err(|_| Why::Damaged)?;
+            if bytes.len() as u64 > budget {
+                return Err(Why::TooLarge);
+            }
+            budget -= bytes.len() as u64;
+            Ok(bytes)
+        };
+
+    let has = |name: &str| names.iter().any(|n| n == name);
+    let mut text = String::new();
+    let result: Result<(), Why> = (|| {
+        if has("[Content_Types].xml") {
+            // Office Open XML: the parts that hold what a person wrote
+            let mut shared = Vec::new();
+            if has("xl/sharedStrings.xml") {
+                shared = xml_strings(&read(&mut archive, "xl/sharedStrings.xml")?, "si");
+            }
+            for name in names.iter().filter(|n| ooxml_text_part(n)) {
+                let xml = read(&mut archive, name)?;
+                if name.starts_with("xl/worksheets/") {
+                    xlsx_sheet(&xml, &mut text);
+                } else {
+                    xml_text(&xml, &mut text);
+                }
+                text.push('\n');
+            }
+            text.extend(shared.iter().map(|s| format!("{s}\n")));
+        } else if names.first().is_some_and(|n| n == "mimetype")
+            && read(&mut archive, "mimetype")?.starts_with(b"application/vnd.oasis.opendocument")
+        {
+            // OpenDocument: an encrypted one says so in its manifest
+            if has("META-INF/manifest.xml")
+                && contains(
+                    &read(&mut archive, "META-INF/manifest.xml")?,
+                    b"encryption-data",
+                )
+            {
+                return Err(Why::Encrypted);
+            }
+            for name in ["content.xml", "styles.xml"] {
+                if has(name) {
+                    xml_text(&read(&mut archive, name)?, &mut text);
+                    text.push('\n');
+                }
+            }
+        } else {
+            // An archive: each file inside, one level deep
+            for name in names.iter().filter(|n| !n.ends_with('/')) {
+                let bytes = read(&mut archive, name)?;
+                match extract_at("", Some(name), &bytes, limits, 1) {
+                    Extracted::Text(inner) => {
+                        text.push_str(&inner);
+                        text.push('\n');
+                    }
+                    Extracted::NoText => {}
+                    Extracted::NotInspectable(why) => return Err(why),
+                }
+            }
+        }
+        Ok(())
+    })();
+    match result {
+        Ok(()) => Extracted::Text(text),
+        Err(why) => Extracted::NotInspectable(why),
+    }
+}
+
+fn ooxml_text_part(name: &str) -> bool {
+    let xml = name.ends_with(".xml");
+    xml && (name == "word/document.xml"
+        || [
+            "word/header",
+            "word/footer",
+            "word/footnotes",
+            "word/endnotes",
+            "word/comments",
+        ]
+        .iter()
+        .any(|p| name.starts_with(p))
+        || name.starts_with("xl/worksheets/sheet")
+        || name.starts_with("ppt/slides/slide")
+        || name.starts_with("ppt/notesSlides/"))
+}
+
+fn contains(haystack: &[u8], needle: &[u8]) -> bool {
+    haystack.windows(needle.len()).any(|w| w == needle)
+}
+
+/// The local name of a tag, without its namespace prefix.
+fn local(name: &[u8]) -> &[u8] {
+    name.rsplit(|b| *b == b':').next().unwrap_or(name)
+}
+
+fn push_entity(entity: &[u8], out: &mut String) {
+    match entity {
+        b"lt" => out.push('<'),
+        b"gt" => out.push('>'),
+        b"amp" => out.push('&'),
+        b"apos" => out.push('\''),
+        b"quot" => out.push('"'),
+        _ => {
+            let code = match entity {
+                [b'#', b'x' | b'X', hex @ ..] => std::str::from_utf8(hex)
+                    .ok()
+                    .and_then(|h| u32::from_str_radix(h, 16).ok()),
+                [b'#', dec @ ..] => std::str::from_utf8(dec).ok().and_then(|d| d.parse().ok()),
+                _ => None,
+            };
+            if let Some(c) = code.and_then(char::from_u32) {
+                out.push(c);
+            }
+        }
+    }
+}
+
+/// Every text node, runs joined as written, a new line after each paragraph
+/// or row and a tab after each cell, so a number split across runs is whole
+/// again.
+fn xml_text(xml: &[u8], out: &mut String) {
+    let mut reader = Reader::from_reader(xml);
+    let mut buf = Vec::new();
+    loop {
+        match reader.read_event_into(&mut buf) {
+            Ok(Event::Text(t)) => {
+                if let Ok(text) = t.xml_content(XmlVersion::Implicit1_0) {
+                    out.push_str(&text);
+                }
+            }
+            Ok(Event::CData(t)) => out.push_str(&String::from_utf8_lossy(&t)),
+            Ok(Event::GeneralRef(entity)) => push_entity(&entity, out),
+            Ok(Event::End(e)) => match local(e.name().as_ref()) {
+                b"p" | b"h" | b"tr" | b"row" | b"table-row" | b"br" => out.push('\n'),
+                b"tc" | b"c" | b"table-cell" | b"tab" => out.push('\t'),
+                _ => {}
+            },
+            Ok(Event::Empty(e)) => match local(e.name().as_ref()) {
+                b"br" | b"line-break" => out.push('\n'),
+                b"tab" | b"s" => out.push(' '),
+                _ => {}
+            },
+            Ok(Event::Eof) | Err(_) => break,
+            _ => {}
+        }
+        buf.clear();
+    }
+}
+
+/// The text of each `item` element (a shared string in XLSX).
+fn xml_strings(xml: &[u8], item: &str) -> Vec<String> {
+    let mut reader = Reader::from_reader(xml);
+    let mut buf = Vec::new();
+    let mut items = Vec::new();
+    let mut current: Option<String> = None;
+    loop {
+        match reader.read_event_into(&mut buf) {
+            Ok(Event::Start(e)) if local(e.name().as_ref()) == item.as_bytes() => {
+                current = Some(String::new())
+            }
+            Ok(Event::End(e)) if local(e.name().as_ref()) == item.as_bytes() => {
+                items.extend(current.take());
+            }
+            Ok(Event::Text(t)) => {
+                if let (Some(s), Ok(text)) =
+                    (current.as_mut(), t.xml_content(XmlVersion::Implicit1_0))
+                {
+                    s.push_str(&text);
+                }
+            }
+            Ok(Event::GeneralRef(entity)) => {
+                if let Some(s) = current.as_mut() {
+                    push_entity(&entity, s);
+                }
+            }
+            Ok(Event::Eof) | Err(_) => break,
+            _ => {}
+        }
+        buf.clear();
+    }
+    items
+}
+
+/// A worksheet's cell values: numbers and inline strings. Cells holding a
+/// shared string are skipped here; the shared strings are read whole.
+fn xlsx_sheet(xml: &[u8], out: &mut String) {
+    let mut reader = Reader::from_reader(xml);
+    let mut buf = Vec::new();
+    let mut shared_cell = false;
+    let mut in_value = false;
+    loop {
+        match reader.read_event_into(&mut buf) {
+            Ok(Event::Start(e)) => match local(e.name().as_ref()) {
+                b"c" => {
+                    shared_cell = e
+                        .attributes()
+                        .flatten()
+                        .any(|a| a.key.as_ref() == b"t" && a.value.as_ref() == b"s");
+                }
+                b"v" | b"t" => in_value = true,
+                _ => {}
+            },
+            Ok(Event::End(e)) => match local(e.name().as_ref()) {
+                b"v" | b"t" => in_value = false,
+                b"c" => out.push('\t'),
+                b"row" => out.push('\n'),
+                _ => {}
+            },
+            // A shared string's cell holds only its index: the string itself
+            // is added with the shared strings
+            Ok(Event::Text(t)) if in_value && !shared_cell => {
+                if let Ok(text) = t.xml_content(XmlVersion::Implicit1_0) {
+                    out.push_str(&text);
+                }
+            }
+            Ok(Event::Eof) | Err(_) => break,
+            _ => {}
+        }
+        buf.clear();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::Write;
+    use zip::{ZipWriter, write::SimpleFileOptions};
+
+    fn zip_of(files: &[(&str, &str)]) -> Vec<u8> {
+        let mut zip = ZipWriter::new(Cursor::new(Vec::new()));
+        for (name, body) in files {
+            zip.start_file(*name, SimpleFileOptions::default()).unwrap();
+            zip.write_all(body.as_bytes()).unwrap();
+        }
+        zip.finish().unwrap().into_inner()
+    }
+
+    fn text_of(extracted: Extracted) -> String {
+        match extracted {
+            Extracted::Text(text) => text,
+            other => panic!("expected text, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn plain_text_and_html() {
+        let limits = Limits::default();
+        assert_eq!(
+            text_of(extract("text/plain", None, b"card 4242", &limits)),
+            "card 4242"
+        );
+        let utf16: Vec<u8> = [0xFF, 0xFE]
+            .into_iter()
+            .chain("héllo".encode_utf16().flat_map(u16::to_le_bytes))
+            .collect();
+        assert_eq!(
+            text_of(extract(
+                "application/octet-stream",
+                Some("a.csv"),
+                &utf16,
+                &limits
+            )),
+            "héllo"
+        );
+        let html = "<html><style>p{}</style><p>Card&nbsp;4242</p><script>x()</script><td>a</td><td>b</td></html>";
+        let text = text_of(extract("text/html", None, html.as_bytes(), &limits));
+        assert!(
+            text.contains("Card 4242") && !text.contains("x()") && !text.contains("p{}"),
+            "{text:?}"
+        );
+        assert_eq!(
+            extract("image/png", Some("a.png"), b"\x89PNG....", &limits),
+            Extracted::NoText
+        );
+    }
+
+    #[test]
+    fn docx_joins_split_runs() {
+        let doc = r#"<w:document xmlns:w="w"><w:body><w:p><w:r><w:t>Card 4242 42</w:t></w:r><w:r><w:t>42 4242 4242</w:t></w:r></w:p><w:p><w:r><w:t>A &amp; B</w:t></w:r></w:p></w:body></w:document>"#;
+        let docx = zip_of(&[
+            ("[Content_Types].xml", "<Types/>"),
+            ("word/document.xml", doc),
+        ]);
+        let text = text_of(extract(
+            "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+            Some("a.docx"),
+            &docx,
+            &Limits::default(),
+        ));
+        assert!(text.contains("Card 4242 4242 4242 4242\nA & B"), "{text:?}");
+    }
+
+    #[test]
+    fn xlsx_numbers_and_shared_strings() {
+        let sheet = r#"<worksheet><sheetData><row><c r="A1" t="s"><v>0</v></c><c r="B1"><v>4242424242424242</v></c></row></sheetData></worksheet>"#;
+        let shared = r#"<sst><si><t>IBAN GB29 NWBK 6016 1331 9268 19</t></si></sst>"#;
+        let xlsx = zip_of(&[
+            ("[Content_Types].xml", "<Types/>"),
+            ("xl/sharedStrings.xml", shared),
+            ("xl/worksheets/sheet1.xml", sheet),
+        ]);
+        let text = text_of(extract("", Some("book.xlsx"), &xlsx, &Limits::default()));
+        assert!(
+            text.contains("4242424242424242") && text.contains("GB29 NWBK 6016 1331 9268 19"),
+            "{text:?}"
+        );
+        // The shared string's index isn't read as a value
+        assert!(
+            !text.contains("\t0\t") && !text.starts_with('0'),
+            "{text:?}"
+        );
+    }
+
+    #[test]
+    fn opendocument_and_encrypted_opendocument() {
+        let content = r#"<office:document-content xmlns:text="t"><text:p>SSN 078-05-1120</text:p></office:document-content>"#;
+        let odt = zip_of(&[
+            ("mimetype", "application/vnd.oasis.opendocument.text"),
+            ("content.xml", content),
+        ]);
+        assert!(
+            text_of(extract("", Some("a.odt"), &odt, &Limits::default()))
+                .contains("SSN 078-05-1120")
+        );
+        let manifest = r#"<manifest:manifest><manifest:file-entry><manifest:encryption-data/></manifest:file-entry></manifest:manifest>"#;
+        let locked = zip_of(&[
+            ("mimetype", "application/vnd.oasis.opendocument.text"),
+            ("META-INF/manifest.xml", manifest),
+            ("content.xml", "x"),
+        ]);
+        assert_eq!(
+            extract("", Some("a.odt"), &locked, &Limits::default()),
+            Extracted::NotInspectable(Why::Encrypted)
+        );
+    }
+
+    #[test]
+    fn archives() {
+        let limits = Limits::default();
+        let archive = zip_of(&[
+            ("notes/a.txt", "card 4242424242424242"),
+            ("b.png", "\u{89}PNG"),
+        ]);
+        assert!(
+            text_of(extract("application/zip", Some("x.zip"), &archive, &limits))
+                .contains("4242424242424242")
+        );
+        let nested = zip_of(&[(
+            "inner.zip",
+            std::str::from_utf8(&[b'P', b'K', 3, 4]).unwrap(),
+        )]);
+        assert_eq!(
+            extract("application/zip", Some("x.zip"), &nested, &limits),
+            Extracted::NotInspectable(Why::NestedArchive)
+        );
+
+        // Password-protected
+        let mut zip = ZipWriter::new(Cursor::new(Vec::new()));
+        zip.start_file(
+            "secret.txt",
+            SimpleFileOptions::default().with_aes_encryption(zip::AesMode::Aes256, "pw"),
+        )
+        .unwrap();
+        zip.write_all(b"4242424242424242").unwrap();
+        let locked = zip.finish().unwrap().into_inner();
+        assert_eq!(
+            extract("application/zip", Some("x.zip"), &locked, &limits),
+            Extracted::NotInspectable(Why::Encrypted)
+        );
+
+        // Past the limits
+        let small = Limits {
+            max_unpacked: 10,
+            max_entries: 1,
+        };
+        assert_eq!(
+            extract("application/zip", Some("x.zip"), &archive, &small),
+            Extracted::NotInspectable(Why::TooLarge)
+        );
+        assert_eq!(
+            extract("application/zip", None, b"PK\x03\x04garbage", &limits),
+            Extracted::NotInspectable(Why::Damaged)
+        );
+    }
+
+    #[test]
+    fn not_inspectable_kinds() {
+        let limits = Limits::default();
+        assert_eq!(
+            extract("application/octet-stream", None, b"%PDF-1.7 ...", &limits),
+            Extracted::NotInspectable(Why::Pdf)
+        );
+        let mut ole = OLE_MAGIC.to_vec();
+        ole.extend(std::iter::repeat_n(0, 64));
+        assert_eq!(
+            extract("", Some("old.doc"), &ole, &limits),
+            Extracted::NotInspectable(Why::LegacyOffice)
+        );
+        ole.extend("EncryptedPackage".encode_utf16().flat_map(u16::to_le_bytes));
+        assert_eq!(
+            extract("", Some("new.docx"), &ole, &limits),
+            Extracted::NotInspectable(Why::Encrypted)
+        );
+    }
+}

crates/features/src/mailflow/mod.rs

@@ -0,0 +1,29 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Data loss prevention and mail flow rules (dlp-and-mail-flow-rules spec).
+//!
+//! Mostly pure functions over text and attachment bytes, unit-tested
+//! without a server:
+//!
+//! - [`detectors`]: find identifiers in text (payment cards, IBANs,
+//!   national ID numbers, keys), each by its published format and check
+//!   (§2.3);
+//! - [`words`]: an organization's own word lists and patterns;
+//! - [`extract`]: the text of an attachment, or why it can't be read;
+//! - [`rules`]: what a rule is, its checks, and where rules are kept;
+//! - [`engine`]: rules compiled and run against a message;
+//! - [`cache`]: each node's compiled copy.
+//!
+//! Nothing here writes what it finds anywhere: callers get counts, and the
+//! matched text never leaves the evaluation (§2.7).
+
+pub mod cache;
+pub mod detectors;
+pub mod engine;
+pub mod extract;
+pub mod rules;
+pub mod words;

crates/features/src/mailflow/rules.rs

@@ -0,0 +1,717 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Mail flow rules and DLP rules (dlp-and-mail-flow-rules spec, §2.2–§2.4):
+//! what a rule is, what makes one valid, and where it's kept.
+//!
+//! Kept in the fork's subspace (`store::SUBSPACE_INBUXA`), never in the
+//! registry, so an upstream schema import never touches them. Every key
+//! starts with `R`, then one byte for the kind:
+//!
+//! - `r` + rule id (u32): the rule, as JSON.
+//!
+//! Numbers are big-endian. There are few rules, so they're read whole.
+
+use super::{detectors, words};
+use serde::{Deserialize as SerdeDeserialize, Serialize as SerdeSerialize, de::DeserializeOwned};
+use store::{
+    Deserialize, IterateParams, SUBSPACE_INBUXA, Serialize, Store, ValueKey,
+    write::{AnyClass, BatchBuilder, ValueClass, assert::AssertValue},
+};
+use trc::AddContext;
+
+const FEATURE: u8 = b'R';
+const KIND_RULE: u8 = b'r';
+const CREATE_ATTEMPTS: usize = 5;
+
+/// Longest text a rule may carry (a notice, a disclaimer), in bytes.
+const MAX_TEXT: usize = 16 * 1024;
+/// Most entries in one list (words, addresses, domains).
+const MAX_LIST: usize = 5_000;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum Kind {
+    Dlp,
+    Transport,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum Direction {
+    /// Mail an authenticated sender submits, over SMTP or JMAP.
+    Outgoing,
+    /// Everything else the server accepts.
+    Incoming,
+    Any,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum Position {
+    Top,
+    Bottom,
+}
+
+fn one() -> u32 {
+    1
+}
+
+/// A detector and the least it must find.
+#[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct DetectorMin {
+    pub id: String,
+    #[serde(default = "one")]
+    pub at_least: u32,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(
+    tag = "type",
+    rename_all = "camelCase",
+    rename_all_fields = "camelCase"
+)]
+pub enum Condition {
+    SenderAddress {
+        addresses: Vec<String>,
+    },
+    SenderDomain {
+        domains: Vec<String>,
+    },
+    SenderGroup {
+        groups: Vec<u32>,
+    },
+    SenderTenant {
+        tenants: Vec<u32>,
+    },
+    /// Any recipient is one of these.
+    RecipientAddress {
+        addresses: Vec<String>,
+    },
+    RecipientDomain {
+        domains: Vec<String>,
+    },
+    RecipientGroup {
+        groups: Vec<u32>,
+    },
+    /// Any recipient isn't at a domain this server hosts.
+    RecipientOutside,
+    /// Words or phrases in the subject, body or readable attachments.
+    Words {
+        words: Vec<String>,
+        #[serde(default = "one")]
+        at_least: u32,
+    },
+    /// The organization's regular expression, in the same places.
+    Pattern {
+        pattern: String,
+        #[serde(default = "one")]
+        at_least: u32,
+    },
+    /// A header exists, or its value contains or matches.
+    Header {
+        name: String,
+        #[serde(default)]
+        contains: Option<String>,
+        #[serde(default)]
+        matches: Option<String>,
+    },
+    /// An attachment's declared or detected type starts with one of these.
+    AttachmentType {
+        types: Vec<String>,
+    },
+    AttachmentExtension {
+        extensions: Vec<String>,
+    },
+    AttachmentName {
+        pattern: String,
+    },
+    AttachmentSizeOver {
+        bytes: u64,
+    },
+    AttachmentCountOver {
+        count: u32,
+    },
+    /// An attachment is encrypted, a PDF, a legacy Office file, an archive
+    /// inside an archive, or past the inspection limit.
+    CantBeInspected,
+    MessageSizeOver {
+        bytes: u64,
+    },
+    /// Any of these detectors finds at least its minimum (DLP rules only).
+    Detected {
+        detectors: Vec<DetectorMin>,
+    },
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(
+    tag = "type",
+    rename_all = "camelCase",
+    rename_all_fields = "camelCase"
+)]
+pub enum Action {
+    // Transport actions
+    AddDisclaimer {
+        text: String,
+        #[serde(default)]
+        html: Option<String>,
+        position: Position,
+    },
+    AddHeader {
+        name: String,
+        value: String,
+    },
+    RemoveHeader {
+        name: String,
+    },
+    PrefixSubject {
+        text: String,
+    },
+    AddRecipient {
+        address: String,
+    },
+    Redirect {
+        addresses: Vec<String>,
+    },
+    Refuse {
+        text: String,
+    },
+    Route {
+        queue: String,
+    },
+    // DLP actions
+    Block {
+        notice: String,
+    },
+    Warn {
+        notice: String,
+    },
+    Hold {
+        notice: String,
+        #[serde(default)]
+        notify_sender: bool,
+    },
+}
+
+impl Action {
+    pub fn is_dlp(&self) -> bool {
+        matches!(
+            self,
+            Action::Block { .. } | Action::Warn { .. } | Action::Hold { .. }
+        )
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Rule {
+    #[serde(default)]
+    pub id: u32,
+    pub name: String,
+    #[serde(default)]
+    pub description: String,
+    pub kind: Kind,
+    #[serde(default = "enabled")]
+    pub enabled: bool,
+    #[serde(default)]
+    pub priority: i32,
+    pub direction: Direction,
+    #[serde(default)]
+    pub conditions: Vec<Condition>,
+    #[serde(default)]
+    pub exceptions: Vec<Condition>,
+    pub actions: Vec<Action>,
+    #[serde(default)]
+    pub stop_processing: bool,
+    #[serde(default)]
+    pub created_by: String,
+    #[serde(default)]
+    pub created_at: u64,
+    #[serde(default)]
+    pub updated_at: u64,
+}
+
+fn enabled() -> bool {
+    true
+}
+
+/// Why a rule can't be saved: the property at fault, and a sentence.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Invalid {
+    pub property: &'static str,
+    pub reason: String,
+}
+
+fn invalid(property: &'static str, reason: impl Into<String>) -> Invalid {
+    Invalid {
+        property,
+        reason: reason.into(),
+    }
+}
+
+impl Rule {
+    /// Everything that can be checked without the rest of the server: the
+    /// shape (§2.2, §2.4), the detectors, word lists and patterns.
+    pub fn validate(&self) -> Result<(), Invalid> {
+        if self.name.trim().is_empty() {
+            return Err(invalid("name", "A rule needs a name."));
+        }
+        if self.name.len() > 200 || self.description.len() > MAX_TEXT {
+            return Err(invalid("name", "The name or description is too long."));
+        }
+        if self.actions.is_empty() {
+            return Err(invalid("actions", "A rule needs something to do."));
+        }
+        let dlp_actions = self.actions.iter().filter(|a| a.is_dlp()).count();
+        match self.kind {
+            Kind::Dlp => {
+                if self.direction != Direction::Outgoing {
+                    return Err(invalid("direction", "DLP rules check outgoing mail only."));
+                }
+                if dlp_actions != 1 || self.actions.len() != 1 {
+                    return Err(invalid(
+                        "actions",
+                        "A DLP rule has exactly one action: block, warn or hold.",
+                    ));
+                }
+            }
+            Kind::Transport => {
+                if dlp_actions > 0 {
+                    return Err(invalid(
+                        "actions",
+                        "Block, warn and hold belong to DLP rules.",
+                    ));
+                }
+                if self
+                    .conditions
+                    .iter()
+                    .chain(&self.exceptions)
+                    .any(|c| matches!(c, Condition::Detected { .. }))
+                {
+                    return Err(invalid("conditions", "Detectors belong to DLP rules."));
+                }
+            }
+        }
+        for (property, list) in [
+            ("conditions", &self.conditions),
+            ("exceptions", &self.exceptions),
+        ] {
+            for condition in list {
+                validate_condition(condition).map_err(|reason| invalid(property, reason))?;
+            }
+        }
+        for action in &self.actions {
+            validate_action(action).map_err(|reason| invalid("actions", reason))?;
+        }
+        Ok(())
+    }
+}
+
+fn nonempty_list<T>(list: &[T], what: &str) -> Result<(), String> {
+    if list.is_empty() {
+        Err(format!("The {what} list is empty."))
+    } else if list.len() > MAX_LIST {
+        Err(format!(
+            "The {what} list is longer than {MAX_LIST} entries."
+        ))
+    } else {
+        Ok(())
+    }
+}
+
+fn header_name(name: &str) -> Result<(), String> {
+    if !name.is_empty()
+        && name.len() <= 100
+        && name.bytes().all(|b| b.is_ascii_graphic() && b != b':')
+    {
+        Ok(())
+    } else {
+        Err(format!("\"{name}\" isn't a header name."))
+    }
+}
+
+fn text(value: &str, what: &str) -> Result<(), String> {
+    if value.trim().is_empty() {
+        Err(format!("The {what} is empty."))
+    } else if value.len() > MAX_TEXT {
+        Err(format!("The {what} is longer than {MAX_TEXT} bytes."))
+    } else {
+        Ok(())
+    }
+}
+
+fn validate_condition(condition: &Condition) -> Result<(), String> {
+    match condition {
+        Condition::SenderAddress { addresses } | Condition::RecipientAddress { addresses } => {
+            nonempty_list(addresses, "address")
+        }
+        Condition::SenderDomain { domains } | Condition::RecipientDomain { domains } => {
+            nonempty_list(domains, "domain")
+        }
+        Condition::SenderGroup { groups } | Condition::RecipientGroup { groups } => {
+            nonempty_list(groups, "group")
+        }
+        Condition::SenderTenant { tenants } => nonempty_list(tenants, "tenant"),
+        Condition::Words { words, at_least } => {
+            nonempty_list(words, "word")?;
+            if *at_least == 0 {
+                return Err("The least number of words must be 1 or more.".into());
+            }
+            words::WordList::new(words).map(|_| ())
+        }
+        Condition::Pattern { pattern, at_least } => {
+            if *at_least == 0 {
+                return Err("The least number of matches must be 1 or more.".into());
+            }
+            words::Pattern::new(pattern).map(|_| ())
+        }
+        Condition::Header {
+            name,
+            contains,
+            matches,
+        } => {
+            header_name(name)?;
+            if let Some(pattern) = matches {
+                words::Pattern::new(pattern)?;
+            }
+            if contains.is_some() && matches.is_some() {
+                return Err("A header condition is either contains or matches.".into());
+            }
+            Ok(())
+        }
+        Condition::AttachmentType { types } => nonempty_list(types, "type"),
+        Condition::AttachmentExtension { extensions } => nonempty_list(extensions, "extension"),
+        Condition::AttachmentName { pattern } => words::Pattern::new(pattern).map(|_| ()),
+        Condition::Detected { detectors } => {
+            nonempty_list(detectors, "detector")?;
+            for d in detectors {
+                if detectors::by_id(&d.id).is_none() {
+                    return Err(format!("There is no detector \"{}\".", d.id));
+                }
+                if d.at_least == 0 {
+                    return Err("A detector's least count must be 1 or more.".into());
+                }
+            }
+            Ok(())
+        }
+        Condition::RecipientOutside
+        | Condition::AttachmentSizeOver { .. }
+        | Condition::AttachmentCountOver { .. }
+        | Condition::CantBeInspected
+        | Condition::MessageSizeOver { .. } => Ok(()),
+    }
+}
+
+fn validate_action(action: &Action) -> Result<(), String> {
+    match action {
+        Action::AddDisclaimer { text: t, html, .. } => {
+            text(t, "disclaimer")?;
+            html.as_deref()
+                .map_or(Ok(()), |h| text(h, "disclaimer's HTML"))
+        }
+        Action::AddHeader { name, value } => {
+            header_name(name)?;
+            if value.len() > 998 || value.contains(['\r', '\n']) {
+                Err("A header value is one line of at most 998 characters.".into())
+            } else {
+                Ok(())
+            }
+        }
+        Action::RemoveHeader { name } => header_name(name),
+        Action::PrefixSubject { text: t } => text(t, "subject prefix"),
+        Action::AddRecipient { address } => {
+            if address.contains('@') {
+                Ok(())
+            } else {
+                Err(format!("\"{address}\" isn't an address."))
+            }
+        }
+        Action::Redirect { addresses } => {
+            nonempty_list(addresses, "address")?;
+            match addresses.iter().find(|a| !a.contains('@')) {
+                Some(a) => Err(format!("\"{a}\" isn't an address.")),
+                None => Ok(()),
+            }
+        }
+        Action::Refuse { text: t } => text(t, "refusal text"),
+        Action::Route { queue } => text(queue, "queue"),
+        Action::Block { notice } | Action::Warn { notice } | Action::Hold { notice, .. } => {
+            text(notice, "notice")
+        }
+    }
+}
+
+// --- Storage --------------------------------------------------------------
+
+struct Json<T>(T);
+
+impl<T: SerdeSerialize> Serialize for Json<T> {
+    fn serialize(&self) -> trc::Result<Vec<u8>> {
+        serde_json::to_vec(&self.0).map_err(|err| {
+            trc::StoreEvent::UnexpectedError
+                .into_err()
+                .details("Failed to serialize mail rule")
+                .reason(err)
+        })
+    }
+}
+
+impl<T: DeserializeOwned + Sync + Send> Deserialize for Json<T> {
+    fn deserialize(bytes: &[u8]) -> trc::Result<Self> {
+        serde_json::from_slice(bytes).map(Json).map_err(|err| {
+            trc::StoreEvent::DataCorruption
+                .into_err()
+                .details("Invalid mail rule")
+                .reason(err)
+        })
+    }
+}
+
+fn class(id: u32) -> ValueClass {
+    let mut key = Vec::with_capacity(6);
+    key.push(FEATURE);
+    key.push(KIND_RULE);
+    key.extend_from_slice(&id.to_be_bytes());
+    ValueClass::Any(AnyClass {
+        subspace: SUBSPACE_INBUXA,
+        key,
+    })
+}
+
+fn key(id: u32) -> ValueKey<ValueClass> {
+    ValueKey::from(class(id))
+}
+
+pub async fn get(data: &Store, id: u32) -> trc::Result<Option<Rule>> {
+    Ok(data
+        .get_value::<Json<Rule>>(key(id))
+        .await
+        .caused_by(trc::location!())?
+        .map(|Json(rule)| rule))
+}
+
+/// Every rule, in the order they run: by priority, then oldest first.
+pub async fn all(data: &Store) -> trc::Result<Vec<Rule>> {
+    let mut rules = Vec::new();
+    data.iterate(IterateParams::new(key(0), key(u32::MAX)), |_, value| {
+        if let Ok(Json(rule)) = Json::<Rule>::deserialize(value) {
+            rules.push(rule);
+        }
+        Ok(true)
+    })
+    .await
+    .caused_by(trc::location!())?;
+    rules.sort_by_key(|rule| (rule.priority, rule.id));
+    Ok(rules)
+}
+
+/// Writes a new rule under the next free id, which it returns. Two nodes
+/// creating rules at once can't take the same id: the key must be absent.
+pub async fn create(data: &Store, rule: &Rule) -> trc::Result<u32> {
+    let mut attempt = 0;
+    loop {
+        attempt += 1;
+        let id = all(data).await?.iter().map(|r| r.id).max().unwrap_or(0) + 1;
+        let stored = Rule { id, ..rule.clone() };
+        let mut batch = BatchBuilder::new();
+        batch.assert_value(class(id), AssertValue::None);
+        batch.set(class(id), Json(&stored).serialize()?);
+        match data.write(batch.build_all()).await {
+            Ok(_) => {
+                super::cache::invalidate();
+                return Ok(id);
+            }
+            Err(err)
+                if attempt < CREATE_ATTEMPTS
+                    && matches!(
+                        err.as_ref(),
+                        trc::EventType::Store(trc::StoreEvent::AssertValueFailed)
+                    ) => {}
+            Err(err) => return Err(err.caused_by(trc::location!())),
+        }
+    }
+}
+
+/// Replaces a stored rule (same id).
+pub async fn update(data: &Store, rule: &Rule) -> trc::Result<()> {
+    let mut batch = BatchBuilder::new();
+    batch.set(class(rule.id), Json(rule).serialize()?);
+    data.write(batch.build_all())
+        .await
+        .caused_by(trc::location!())?;
+    super::cache::invalidate();
+    Ok(())
+}
+
+pub async fn delete(data: &Store, id: u32) -> trc::Result<()> {
+    let mut batch = BatchBuilder::new();
+    batch.clear(class(id));
+    data.write(batch.build_all())
+        .await
+        .caused_by(trc::location!())?;
+    super::cache::invalidate();
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn rule(kind: Kind, actions: Vec<Action>) -> Rule {
+        Rule {
+            id: 0,
+            name: "Cards outside".into(),
+            description: String::new(),
+            kind,
+            enabled: true,
+            priority: 0,
+            direction: Direction::Outgoing,
+            conditions: vec![Condition::RecipientOutside],
+            exceptions: vec![],
+            actions,
+            stop_processing: false,
+            created_by: String::new(),
+            created_at: 0,
+            updated_at: 0,
+        }
+    }
+
+    #[test]
+    fn wire_format() {
+        let json = r#"{"name":"Cards","kind":"dlp","direction":"outgoing",
+            "conditions":[{"type":"recipientOutside"},{"type":"detected","detectors":[{"id":"payment-card","atLeast":5}]}],
+            "actions":[{"type":"hold","notice":"Held for review","notifySender":true}]}"#;
+        let parsed: Rule = serde_json::from_str(json).unwrap();
+        assert!(parsed.enabled);
+        assert_eq!(
+            parsed.conditions[1],
+            Condition::Detected {
+                detectors: vec![DetectorMin {
+                    id: "payment-card".into(),
+                    at_least: 5
+                }]
+            }
+        );
+        assert_eq!(
+            parsed.actions[0],
+            Action::Hold {
+                notice: "Held for review".into(),
+                notify_sender: true
+            }
+        );
+        assert!(parsed.validate().is_ok());
+        let back = serde_json::to_value(&parsed).unwrap();
+        assert_eq!(back["actions"][0]["notifySender"], true);
+    }
+
+    #[test]
+    fn dlp_rules_have_one_dlp_action_on_outgoing_mail() {
+        let block = Action::Block {
+            notice: "No.".into(),
+        };
+        assert!(rule(Kind::Dlp, vec![block.clone()]).validate().is_ok());
+        let two = rule(
+            Kind::Dlp,
+            vec![
+                block.clone(),
+                Action::Warn {
+                    notice: "Hm.".into(),
+                },
+            ],
+        );
+        assert_eq!(two.validate().unwrap_err().property, "actions");
+        let mixed = rule(
+            Kind::Dlp,
+            vec![block.clone(), Action::PrefixSubject { text: "[x]".into() }],
+        );
+        assert_eq!(mixed.validate().unwrap_err().property, "actions");
+        let mut inbound = rule(Kind::Dlp, vec![block.clone()]);
+        inbound.direction = Direction::Incoming;
+        assert_eq!(inbound.validate().unwrap_err().property, "direction");
+        assert_eq!(
+            rule(Kind::Transport, vec![block])
+                .validate()
+                .unwrap_err()
+                .property,
+            "actions"
+        );
+    }
+
+    #[test]
+    fn conditions_and_actions_are_checked() {
+        let disclaimer = Action::AddDisclaimer {
+            text: "Sent from Example Co.".into(),
+            html: None,
+            position: Position::Bottom,
+        };
+        let mut r = rule(Kind::Transport, vec![disclaimer]);
+        assert!(r.validate().is_ok());
+        r.conditions.push(Condition::Detected {
+            detectors: vec![DetectorMin {
+                id: "iban".into(),
+                at_least: 1,
+            }],
+        });
+        assert_eq!(r.validate().unwrap_err().property, "conditions");
+
+        let mut r = rule(
+            Kind::Dlp,
+            vec![Action::Block {
+                notice: "No.".into(),
+            }],
+        );
+        r.conditions = vec![Condition::Detected {
+            detectors: vec![DetectorMin {
+                id: "nope".into(),
+                at_least: 1,
+            }],
+        }];
+        assert!(r.validate().unwrap_err().reason.contains("nope"));
+        r.conditions = vec![Condition::Pattern {
+            pattern: "(".into(),
+            at_least: 1,
+        }];
+        assert!(r.validate().is_err());
+        r.conditions = vec![Condition::Words {
+            words: vec![],
+            at_least: 1,
+        }];
+        assert!(r.validate().is_err());
+        r.exceptions = vec![Condition::Header {
+            name: "X-Bad: yes".into(),
+            contains: None,
+            matches: None,
+        }];
+        r.conditions = vec![];
+        assert_eq!(r.validate().unwrap_err().property, "exceptions");
+
+        let header = rule(
+            Kind::Transport,
+            vec![Action::AddHeader {
+                name: "X-Tag".into(),
+                value: "a\r\nBcc: x@y".into(),
+            }],
+        );
+        assert!(header.validate().is_err());
+        let redirect = rule(
+            Kind::Transport,
+            vec![Action::Redirect {
+                addresses: vec!["nobody".into()],
+            }],
+        );
+        assert!(redirect.validate().is_err());
+        let mut unnamed = rule(
+            Kind::Transport,
+            vec![Action::RemoveHeader {
+                name: "X-Tag".into(),
+            }],
+        );
+        unnamed.name = " ".into();
+        assert_eq!(unnamed.validate().unwrap_err().property, "name");
+    }
+}

crates/features/src/mailflow/words.rs

@@ -0,0 +1,109 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! An organization's own word lists and patterns (§2.3). Both count
+//! occurrences, not distinct values: "confidential" three times is three.
+
+use aho_corasick::{AhoCorasick, AhoCorasickBuilder, MatchKind};
+use regex::{Regex, RegexBuilder};
+
+/// How large a compiled pattern may grow. Keeps a rule someone writes from
+/// making every message slow to send.
+const PATTERN_SIZE_LIMIT: usize = 1 << 20;
+
+/// Words and phrases, matched whole and ignoring case.
+#[derive(Debug, Clone)]
+pub struct WordList {
+    matcher: AhoCorasick,
+}
+
+impl WordList {
+    /// Builds a list from words or phrases; empty entries are skipped.
+    pub fn new<I, S>(words: I) -> Result<Self, String>
+    where
+        I: IntoIterator<Item = S>,
+        S: AsRef<str>,
+    {
+        let words: Vec<String> = words
+            .into_iter()
+            .map(|w| w.as_ref().trim().to_lowercase())
+            .filter(|w| !w.is_empty())
+            .collect();
+        if words.is_empty() {
+            return Err("The list has no words".into());
+        }
+        AhoCorasickBuilder::new()
+            .match_kind(MatchKind::LeftmostLongest)
+            .build(&words)
+            .map(|matcher| Self { matcher })
+            .map_err(|err| err.to_string())
+    }
+
+    /// How many times any word of the list appears in `text`.
+    pub fn count(&self, text: &str) -> usize {
+        let text = text.to_lowercase();
+        self.matcher
+            .find_iter(&text)
+            .filter(|m| super::detectors::stands_alone(&text, m.start(), m.end()))
+            .count()
+    }
+}
+
+/// An organization's regular expression.
+#[derive(Debug, Clone)]
+pub struct Pattern {
+    regex: Regex,
+}
+
+impl Pattern {
+    /// Compiles `pattern`, or says why it can't be used. Matching ignores
+    /// case unless the pattern turns that off with `(?-i)`.
+    pub fn new(pattern: &str) -> Result<Self, String> {
+        RegexBuilder::new(pattern)
+            .case_insensitive(true)
+            .size_limit(PATTERN_SIZE_LIMIT)
+            .build()
+            .map(|regex| Self { regex })
+            .map_err(|err| err.to_string())
+    }
+
+    /// How many times the pattern matches in `text`.
+    pub fn count(&self, text: &str) -> usize {
+        self.regex.find_iter(text).filter(|m| !m.is_empty()).count()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn words_whole_and_any_case() {
+        let list = WordList::new(["Project Falcon", "confidential", " "]).unwrap();
+        assert_eq!(
+            list.count(
+                "CONFIDENTIAL: project falcon notes. Not confidentiality, not projectfalcon."
+            ),
+            2
+        );
+        assert_eq!(list.count("Confidential, confidential and confidential"), 3);
+        // Non-ASCII case folding
+        let list = WordList::new(["GEHEIM", "Straße"]).unwrap();
+        assert_eq!(list.count("streng geheim, STRASSE ist nicht Straße"), 2);
+        assert!(WordList::new(["", "  "]).is_err());
+    }
+
+    #[test]
+    fn patterns() {
+        let pattern = Pattern::new(r"\bPRJ-\d{4}\b").unwrap();
+        assert_eq!(pattern.count("prj-1234 and PRJ-5678, not PRJ-12"), 2);
+        assert!(Pattern::new("(unclosed").is_err());
+        // Too large to compile within the limit
+        assert!(Pattern::new(r"\w{1000}\w{1000}\w{1000}").is_err());
+        // Empty matches don't count
+        assert_eq!(Pattern::new("x*").unwrap().count("abc"), 0);
+    }
+}

crates/jmap-proto/src/object/inbuxa_mail_rule.rs

@@ -0,0 +1,218 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:MailRule/get` and `/set` under `urn:inbuxa:jmap`: mail flow rules
+//! and DLP rules (dlp-and-mail-flow-rules spec, §2.2). `kind` says which,
+//! and which permissions reach it. The set call's `reason` argument, if
+//! given, goes into the audit log with the change.
+
+use crate::{
+    object::{AnyId, JmapObject, JmapObjectId},
+    request::deserialize::DeserializeArguments,
+};
+use jmap_tools::{Element, Key, Property};
+use std::{borrow::Cow, str::FromStr};
+use types::id::Id;
+
+#[derive(Debug, Clone, Default)]
+pub struct MailRule;
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum MailRuleProperty {
+    Id,
+    Name,
+    Description,
+    /// `dlp` or `transport`.
+    Kind,
+    Enabled,
+    /// Lower runs first.
+    Priority,
+    /// `outgoing`, `incoming` or `any`.
+    Direction,
+    Conditions,
+    Exceptions,
+    Actions,
+    StopProcessing,
+    CreatedBy,
+    CreatedAt,
+    UpdatedAt,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum MailRuleValue {
+    Id(Id),
+}
+
+impl Property for MailRuleProperty {
+    fn try_parse(parent: Option<&Key<'_, Self>>, value: &str) -> Option<Self> {
+        // Keys inside conditions and actions stay plain keys
+        match parent {
+            None => MailRuleProperty::parse(value),
+            Some(_) => None,
+        }
+    }
+
+    fn to_cow(&self) -> Cow<'static, str> {
+        match self {
+            MailRuleProperty::Id => "id",
+            MailRuleProperty::Name => "name",
+            MailRuleProperty::Description => "description",
+            MailRuleProperty::Kind => "kind",
+            MailRuleProperty::Enabled => "enabled",
+            MailRuleProperty::Priority => "priority",
+            MailRuleProperty::Direction => "direction",
+            MailRuleProperty::Conditions => "conditions",
+            MailRuleProperty::Exceptions => "exceptions",
+            MailRuleProperty::Actions => "actions",
+            MailRuleProperty::StopProcessing => "stopProcessing",
+            MailRuleProperty::CreatedBy => "createdBy",
+            MailRuleProperty::CreatedAt => "createdAt",
+            MailRuleProperty::UpdatedAt => "updatedAt",
+        }
+        .into()
+    }
+}
+
+impl MailRuleProperty {
+    fn parse(value: &str) -> Option<Self> {
+        hashify::tiny_map!(value.as_bytes(),
+            b"id" => MailRuleProperty::Id,
+            b"name" => MailRuleProperty::Name,
+            b"description" => MailRuleProperty::Description,
+            b"kind" => MailRuleProperty::Kind,
+            b"enabled" => MailRuleProperty::Enabled,
+            b"priority" => MailRuleProperty::Priority,
+            b"direction" => MailRuleProperty::Direction,
+            b"conditions" => MailRuleProperty::Conditions,
+            b"exceptions" => MailRuleProperty::Exceptions,
+            b"actions" => MailRuleProperty::Actions,
+            b"stopProcessing" => MailRuleProperty::StopProcessing,
+            b"createdBy" => MailRuleProperty::CreatedBy,
+            b"createdAt" => MailRuleProperty::CreatedAt,
+            b"updatedAt" => MailRuleProperty::UpdatedAt,
+        )
+    }
+}
+
+impl FromStr for MailRuleProperty {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        MailRuleProperty::parse(s).ok_or(())
+    }
+}
+
+impl Element for MailRuleValue {
+    type Property = MailRuleProperty;
+
+    fn try_parse<P>(key: &Key<'_, Self::Property>, value: &str) -> Option<Self> {
+        match key {
+            Key::Property(MailRuleProperty::Id) => Id::from_str(value).ok().map(MailRuleValue::Id),
+            _ => None,
+        }
+    }
+
+    fn to_cow(&self) -> Cow<'static, str> {
+        match self {
+            MailRuleValue::Id(id) => id.to_string().into(),
+        }
+    }
+}
+
+/// The set call's own argument: why, for the audit log.
+#[derive(Debug, Clone, Default)]
+pub struct MailRuleSetArguments {
+    pub reason: Option<String>,
+}
+
+impl<'de> DeserializeArguments<'de> for MailRuleSetArguments {
+    fn deserialize_argument<A>(&mut self, key: &str, map: &mut A) -> Result<(), A::Error>
+    where
+        A: serde::de::MapAccess<'de>,
+    {
+        if key == "reason" {
+            self.reason = map.next_value()?;
+        } else {
+            let _ = map.next_value::<serde::de::IgnoredAny>()?;
+        }
+        Ok(())
+    }
+}
+
+impl JmapObject for MailRule {
+    type Property = MailRuleProperty;
+
+    type Element = MailRuleValue;
+
+    type Id = Id;
+
+    type Filter = ();
+
+    type Comparator = ();
+
+    type GetArguments = ();
+
+    type SetArguments<'de> = MailRuleSetArguments;
+
+    type QueryArguments = ();
+
+    type CopyArguments = ();
+
+    type ParseArguments = ();
+
+    const ID_PROPERTY: Self::Property = MailRuleProperty::Id;
+}
+
+impl From<Id> for MailRuleValue {
+    fn from(id: Id) -> Self {
+        MailRuleValue::Id(id)
+    }
+}
+
+impl JmapObjectId for MailRuleValue {
+    fn as_id(&self) -> Option<Id> {
+        match self {
+            MailRuleValue::Id(id) => Some(*id),
+        }
+    }
+
+    fn as_any_id(&self) -> Option<AnyId> {
+        match self {
+            MailRuleValue::Id(id) => Some(AnyId::Id(*id)),
+        }
+    }
+
+    fn as_id_ref(&self) -> Option<&str> {
+        None
+    }
+
+    fn try_set_id(&mut self, new_id: AnyId) -> bool {
+        if let AnyId::Id(id) = new_id {
+            *self = MailRuleValue::Id(id);
+            true
+        } else {
+            false
+        }
+    }
+}
+
+impl JmapObjectId for MailRuleProperty {
+    fn as_id(&self) -> Option<Id> {
+        None
+    }
+
+    fn as_any_id(&self) -> Option<AnyId> {
+        None
+    }
+
+    fn as_id_ref(&self) -> Option<&str> {
+        None
+    }
+
+    fn try_set_id(&mut self, _: AnyId) -> bool {
+        false
+    }
+}

crates/jmap-proto/src/object/mod.rs

@@ -28,6 +28,7 @@ pub mod inbuxa_data_inventory; // inbuxa: personal-data catalog
 pub mod inbuxa_inventory_snapshot; // inbuxa: personal-data catalog
 pub mod inbuxa_audit; // inbuxa: the audit log
 pub mod inbuxa_legal_hold; // inbuxa: legal hold
+pub mod inbuxa_mail_rule; // inbuxa: DLP and mail flow rules
 pub mod inbuxa_hold_export; // inbuxa: legal hold exports
 pub mod inbuxa_explanation; // inbuxa: "Explain this" with the local model
 pub mod inbuxa_protocol_policy; // inbuxa: legacy protocols off

crates/jmap-proto/src/references/eval.rs

@@ -82,6 +82,9 @@ impl Response<'_> {
                         GetResponseMethod::LegalHold(response) => {
                             response.eval_jptr(path, &mut results)
                         }
+                        GetResponseMethod::MailRule(response) => {
+                            response.eval_jptr(path, &mut results)
+                        }
                         GetResponseMethod::HoldExport(response) => {
                             response.eval_jptr(path, &mut results)
                         }

crates/jmap-proto/src/references/resolve.rs

@@ -53,6 +53,7 @@ impl Response<'_> {
                 GetRequestMethod::AuditSettings(request) => request.resolve_references(self)?,
                 GetRequestMethod::AccountLock(request) => request.resolve_references(self)?,
                 GetRequestMethod::LegalHold(request) => request.resolve_references(self)?,
+                GetRequestMethod::MailRule(request) => request.resolve_references(self)?,
                 GetRequestMethod::HoldExport(request) => request.resolve_references(self)?,
                 GetRequestMethod::ProtocolPolicy(request) => request.resolve_references(self)?,
                 GetRequestMethod::TenantProtocolPolicy(request) => {
@@ -122,6 +123,9 @@ impl Response<'_> {
                 SetRequestMethod::LegalHold(request) => {
                     request.resolve_references(self, 1, false)?
                 }
+                SetRequestMethod::MailRule(request) => {
+                    request.resolve_references(self, 1, false)?
+                }
                 SetRequestMethod::HoldExport(request) => {
                     request.resolve_references(self, 1, false)?
                 }

crates/jmap-proto/src/request/method.rs

@@ -65,6 +65,8 @@ pub enum MethodObject {
     LegalHold,
     HoldExport,
     ProtocolPolicy,
+    // inbuxa: DLP and mail flow rules
+    MailRule,
     TenantProtocolPolicy,
 }
 
@@ -102,7 +104,8 @@ impl MethodObject {
             | MethodObject::AuditVerification
             | MethodObject::AccountLock
             | MethodObject::LegalHold
-            | MethodObject::HoldExport => Capability::Inbuxa,
+            | MethodObject::HoldExport
+            | MethodObject::MailRule => Capability::Inbuxa,
             MethodObject::ProtocolPolicy => Capability::Inbuxa,
             MethodObject::TenantProtocolPolicy => Capability::Inbuxa,
         }
@@ -296,6 +299,8 @@ impl MethodName {
             (MethodFunction::Set, MethodObject::AccountLock) => "inbuxa:AccountLock/set",
             (MethodFunction::Get, MethodObject::LegalHold) => "inbuxa:LegalHold/get",
             (MethodFunction::Set, MethodObject::LegalHold) => "inbuxa:LegalHold/set",
+            (MethodFunction::Get, MethodObject::MailRule) => "inbuxa:MailRule/get",
+            (MethodFunction::Set, MethodObject::MailRule) => "inbuxa:MailRule/set",
             (MethodFunction::Get, MethodObject::HoldExport) => "inbuxa:HoldExport/get",
             (MethodFunction::Set, MethodObject::HoldExport) => "inbuxa:HoldExport/set",
             (MethodFunction::Set, MethodObject::AuditVerification) => {
@@ -448,6 +453,8 @@ impl MethodName {
             "inbuxa:AccountLock/set" => (MethodObject::AccountLock, MethodFunction::Set),
             "inbuxa:LegalHold/get" => (MethodObject::LegalHold, MethodFunction::Get),
             "inbuxa:LegalHold/set" => (MethodObject::LegalHold, MethodFunction::Set),
+            "inbuxa:MailRule/get" => (MethodObject::MailRule, MethodFunction::Get),
+            "inbuxa:MailRule/set" => (MethodObject::MailRule, MethodFunction::Set),
             "inbuxa:HoldExport/get" => (MethodObject::HoldExport, MethodFunction::Get),
             "inbuxa:HoldExport/set" => (MethodObject::HoldExport, MethodFunction::Set),
             "inbuxa:AuditVerification/set" => (MethodObject::AuditVerification, MethodFunction::Set),
@@ -518,6 +525,7 @@ impl Display for MethodObject {
             MethodObject::AuditVerification => "inbuxa:AuditVerification",
             MethodObject::AccountLock => "inbuxa:AccountLock",
             MethodObject::LegalHold => "inbuxa:LegalHold",
+            MethodObject::MailRule => "inbuxa:MailRule",
             MethodObject::HoldExport => "inbuxa:HoldExport",
             MethodObject::ProtocolPolicy => "inbuxa:ProtocolPolicy",
             MethodObject::TenantProtocolPolicy => "inbuxa:TenantProtocolPolicy",

crates/jmap-proto/src/request/mod.rs

@@ -123,6 +123,7 @@ pub enum GetRequestMethod {
     AuditSettings(Box<GetRequest<crate::object::inbuxa_audit::AuditSettings>>),
     AccountLock(Box<GetRequest<crate::object::inbuxa_account_lock::AccountLock>>),
     LegalHold(Box<GetRequest<crate::object::inbuxa_legal_hold::LegalHold>>),
+    MailRule(Box<GetRequest<crate::object::inbuxa_mail_rule::MailRule>>),
     HoldExport(Box<GetRequest<crate::object::inbuxa_hold_export::HoldExport>>),
     ProtocolPolicy(Box<GetRequest<crate::object::inbuxa_protocol_policy::ProtocolPolicy>>),
     TenantProtocolPolicy(
@@ -158,6 +159,7 @@ pub enum SetRequestMethod<'x> {
     AuditVerification(Box<SetRequest<'x, crate::object::inbuxa_audit::AuditVerification>>),
     AccountLock(Box<SetRequest<'x, crate::object::inbuxa_account_lock::AccountLock>>),
     LegalHold(Box<SetRequest<'x, crate::object::inbuxa_legal_hold::LegalHold>>),
+    MailRule(Box<SetRequest<'x, crate::object::inbuxa_mail_rule::MailRule>>),
     HoldExport(Box<SetRequest<'x, crate::object::inbuxa_hold_export::HoldExport>>),
     ProtocolPolicy(Box<SetRequest<'x, crate::object::inbuxa_protocol_policy::ProtocolPolicy>>),
     TenantProtocolPolicy(

crates/jmap-proto/src/request/parser.rs

@@ -609,6 +609,21 @@ impl<'de> Visitor<'de> for CallVisitor {
                     return Err(de::Error::invalid_length(1, &self));
                 }
             },
+            // inbuxa: DLP and mail flow rules
+            (MethodFunction::Get, MethodObject::MailRule) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::MailRule(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
+            (MethodFunction::Set, MethodObject::MailRule) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Set(SetRequestMethod::MailRule(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
             // inbuxa: legal hold
             (MethodFunction::Get, MethodObject::LegalHold) => match seq.next_element() {
                 Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::LegalHold(value)),

crates/jmap-proto/src/response/mod.rs

@@ -110,6 +110,7 @@ pub enum GetResponseMethod {
     AuditSettings(GetResponse<crate::object::inbuxa_audit::AuditSettings>),
     AccountLock(GetResponse<crate::object::inbuxa_account_lock::AccountLock>),
     LegalHold(GetResponse<crate::object::inbuxa_legal_hold::LegalHold>),
+    MailRule(GetResponse<crate::object::inbuxa_mail_rule::MailRule>),
     HoldExport(GetResponse<crate::object::inbuxa_hold_export::HoldExport>),
     ProtocolPolicy(GetResponse<crate::object::inbuxa_protocol_policy::ProtocolPolicy>),
     TenantProtocolPolicy(
@@ -145,6 +146,7 @@ pub enum SetResponseMethod {
     AuditVerification(Box<SetResponse<crate::object::inbuxa_audit::AuditVerification>>),
     AccountLock(Box<SetResponse<crate::object::inbuxa_account_lock::AccountLock>>),
     LegalHold(Box<SetResponse<crate::object::inbuxa_legal_hold::LegalHold>>),
+    MailRule(Box<SetResponse<crate::object::inbuxa_mail_rule::MailRule>>),
     HoldExport(Box<SetResponse<crate::object::inbuxa_hold_export::HoldExport>>),
     Explanation(Box<SetResponse<crate::object::inbuxa_explanation::Explanation>>),
     ProtocolPolicy(Box<SetResponse<crate::object::inbuxa_protocol_policy::ProtocolPolicy>>),
@@ -799,6 +801,18 @@ impl<'x> From<SetResponse<crate::object::inbuxa_account_lock::AccountLock>> for
 }
 
 // inbuxa: legal hold
+impl<'x> From<GetResponse<crate::object::inbuxa_mail_rule::MailRule>> for ResponseMethod<'x> {
+    fn from(value: GetResponse<crate::object::inbuxa_mail_rule::MailRule>) -> Self {
+        ResponseMethod::Get(GetResponseMethod::MailRule(value))
+    }
+}
+
+impl<'x> From<SetResponse<crate::object::inbuxa_mail_rule::MailRule>> for ResponseMethod<'x> {
+    fn from(value: SetResponse<crate::object::inbuxa_mail_rule::MailRule>) -> Self {
+        ResponseMethod::Set(SetResponseMethod::MailRule(Box::new(value)))
+    }
+}
+
 impl<'x> From<GetResponse<crate::object::inbuxa_legal_hold::LegalHold>> for ResponseMethod<'x> {
     fn from(value: GetResponse<crate::object::inbuxa_legal_hold::LegalHold>) -> Self {
         ResponseMethod::Get(GetResponseMethod::LegalHold(value))

crates/jmap/src/api/auth.rs

@@ -103,6 +103,16 @@ impl JmapAuthorization for AccessToken {
                 // inbuxa: account lock (AL-12)
                 GetRequestMethod::AccountLock(_) => Permission::SysAccountLockGet,
                 GetRequestMethod::LegalHold(_) => Permission::SysLegalHoldGet,
+                // inbuxa: DLP and mail flow rules share an object; either
+                // permission reaches it, and the handler shows each kind
+                // only to those who may see it
+                GetRequestMethod::MailRule(_) => {
+                    if self.has_permission(Permission::SysMailRuleGet) {
+                        Permission::SysMailRuleGet
+                    } else {
+                        Permission::SysDlpPolicyGet
+                    }
+                }
                 GetRequestMethod::HoldExport(_) => Permission::SysLegalHoldExport,
                 // inbuxa: legacy protocols off. It takes listeners away and
                 // puts them back, so it takes the listener's permissions
@@ -247,6 +257,19 @@ impl JmapAuthorization for AccessToken {
                         Permission::SysLegalHoldUpdate,
                         Permission::SysLegalHoldUpdate,
                     ),
+                    // inbuxa: DLP and mail flow rules: either change
+                    // permission gets in; the handler checks each rule's kind
+                    SetRequestMethod::MailRule(_) => {
+                        if self.has_permission(Permission::SysMailRuleUpdate)
+                            || self.has_permission(Permission::SysDlpPolicyUpdate)
+                        {
+                            Ok(())
+                        } else {
+                            Err(trc::JmapEvent::Forbidden
+                                .into_err()
+                                .details("You are not authorized to change mail rules"))
+                        }
+                    }
                     // inbuxa: LH-12, exporting held data
                     SetRequestMethod::HoldExport(s) => validate_set(
                         s,
@@ -407,6 +430,7 @@ impl JmapAuthorization for AccessToken {
                 | MethodObject::AccountLock
                 | MethodObject::LegalHold
                 | MethodObject::HoldExport
+                | MethodObject::MailRule
                 | MethodObject::ProtocolPolicy
                 | MethodObject::TenantProtocolPolicy => Permission::JmapEmailChanges,
                 // inbuxa: x:MaskedEmail/changes reads what /get reads

crates/jmap/src/api/request.rs

@@ -279,6 +279,9 @@ impl RequestHandler for Server {
                                     SetResponseMethod::LegalHold(set_response) => {
                                         set_response.update_created_ids(&mut response);
                                     }
+                                    SetResponseMethod::MailRule(set_response) => {
+                                        set_response.update_created_ids(&mut response);
+                                    }
                                     SetResponseMethod::HoldExport(set_response) => {
                                         set_response.update_created_ids(&mut response);
                                     }
@@ -486,6 +489,11 @@ impl RequestHandler for Server {
                     resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
                     crate::inbuxa::legal_hold::get(self, *req).await?.into()
                 }
+                // inbuxa: DLP and mail flow rules
+                GetRequestMethod::MailRule(mut req) => {
+                    resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
+                    crate::inbuxa::mail_rule::get(self, access_token, *req).await?.into()
+                }
                 // inbuxa: the audit log (AU-9)
                 GetRequestMethod::AuditEvent(mut req) => {
                     resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
@@ -910,6 +918,22 @@ impl RequestHandler for Server {
                     .await?
                     .into()
                 }
+                SetRequestMethod::MailRule(mut req) => {
+                    resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
+                    let reason = req.arguments.reason.clone();
+                    crate::inbuxa::audit::recorded(
+                        self,
+                        access_token,
+                        session,
+                        &method_name.obj.to_string(),
+                        None,
+                        reason,
+                        *req,
+                        |req| Box::pin(crate::inbuxa::mail_rule::set(self, access_token, req)),
+                    )
+                    .await?
+                    .into()
+                }
                 SetRequestMethod::AuditExport(mut req) => {
                     resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
                     crate::inbuxa::audit_log::export_set(self, access_token, session, *req)

crates/jmap/src/changes/get.rs

@@ -429,6 +429,7 @@ impl IntermediateChangesResponse {
             | MethodObject::AccountLock
             | MethodObject::LegalHold
             | MethodObject::HoldExport
+            | MethodObject::MailRule
             | MethodObject::ProtocolPolicy
             | MethodObject::TenantProtocolPolicy
             | MethodObject::Registry(_) => unreachable!(),

crates/jmap/src/inbuxa/mail_rule.rs

@@ -0,0 +1,327 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:MailRule` (dlp-and-mail-flow-rules spec, §2.2, §2.8): mail flow
+//! rules and DLP rules. One object, two kinds, each with its own
+//! permissions: `sysMailRuleGet`/`Update` for transport rules,
+//! `sysDlpPolicyGet`/`Update` for DLP rules. Rules are the server's: nobody
+//! in a tenant reaches them (settled answer 3). The request layer records
+//! every change in the audit log.
+
+use common::{Server, auth::AccessToken};
+use inbuxa_features::mailflow::rules::{self, Kind, Rule};
+use jmap_proto::{
+    error::set::SetError,
+    method::{
+        get::{GetRequest, GetResponse},
+        set::{SetRequest, SetResponse},
+    },
+    object::inbuxa_mail_rule::{MailRule, MailRuleProperty as P, MailRuleValue},
+    request::IntoValid,
+    types::date::UTCDate,
+};
+use jmap_tools::{Key, Map, Property, Value};
+use registry::schema::enums::Permission;
+use std::borrow::Cow;
+use store::write::now;
+use types::id::Id;
+
+type RValue = Value<'static, P, MailRuleValue>;
+
+const ALL: &[P] = &[
+    P::Id,
+    P::Name,
+    P::Description,
+    P::Kind,
+    P::Enabled,
+    P::Priority,
+    P::Direction,
+    P::Conditions,
+    P::Exceptions,
+    P::Actions,
+    P::StopProcessing,
+    P::CreatedBy,
+    P::CreatedAt,
+    P::UpdatedAt,
+];
+
+/// Properties the server sets; a client that sends them is refused.
+const SERVER_SET: &[P] = &[P::Id, P::CreatedBy, P::CreatedAt, P::UpdatedAt];
+
+fn can_see(access_token: &AccessToken, kind: Kind) -> bool {
+    access_token.has_permission(match kind {
+        Kind::Dlp => Permission::SysDlpPolicyGet,
+        Kind::Transport => Permission::SysMailRuleGet,
+    })
+}
+
+fn can_change(access_token: &AccessToken, kind: Kind) -> bool {
+    access_token.has_permission(match kind {
+        Kind::Dlp => Permission::SysDlpPolicyUpdate,
+        Kind::Transport => Permission::SysMailRuleUpdate,
+    })
+}
+
+fn server_level(access_token: &AccessToken) -> trc::Result<()> {
+    if access_token.tenant_id().is_some() {
+        Err(trc::JmapEvent::Forbidden
+            .into_err()
+            .details("Mail rules are the server's."))
+    } else {
+        Ok(())
+    }
+}
+
+fn json_to_value(json: serde_json::Value) -> RValue {
+    match json {
+        serde_json::Value::Null => Value::Null,
+        serde_json::Value::Bool(b) => Value::Bool(b),
+        serde_json::Value::Number(n) => {
+            if let Some(n) = n.as_u64() {
+                Value::Number(n.into())
+            } else if let Some(n) = n.as_i64() {
+                Value::Number(n.into())
+            } else {
+                Value::Number(n.as_f64().unwrap_or_default().into())
+            }
+        }
+        serde_json::Value::String(s) => Value::Str(Cow::Owned(s)),
+        serde_json::Value::Array(items) => {
+            Value::Array(items.into_iter().map(json_to_value).collect())
+        }
+        serde_json::Value::Object(map) => {
+            let mut out = Map::with_capacity(map.len());
+            for (key, value) in map {
+                out.insert_unchecked(Key::Owned(key), json_to_value(value));
+            }
+            Value::Object(out)
+        }
+    }
+}
+
+fn date(seconds: u64) -> RValue {
+    Value::Str(UTCDate::from_timestamp(seconds as i64).to_string().into())
+}
+
+fn to_value(rule: &Rule, properties: &[P]) -> RValue {
+    let json = serde_json::to_value(rule).unwrap_or_default();
+    let mut out = Map::with_capacity(properties.len());
+    for property in properties {
+        let value = match property {
+            P::Id => Value::Element(MailRuleValue::Id(Id::from(rule.id))),
+            P::CreatedAt => date(rule.created_at),
+            P::UpdatedAt => date(rule.updated_at),
+            other => json
+                .get(other.to_cow().as_ref())
+                .cloned()
+                .map_or(Value::Null, json_to_value),
+        };
+        out.insert_unchecked(Key::Property(property.clone()), value);
+    }
+    Value::Object(out)
+}
+
+/// A rule as sent: its JSON object, top-level keys only those a client may
+/// set.
+fn client_json(value: Value<'_, P, MailRuleValue>) -> Result<serde_json::Map<String, serde_json::Value>, SetError<P>> {
+    let mut map = serde_json::Map::new();
+    for (key, value) in value.into_expanded_object() {
+        match &key {
+            Key::Property(p) if SERVER_SET.contains(p) => {
+                return Err(SetError::invalid_properties()
+                    .with_property(p.clone())
+                    .with_description("The server sets this."));
+            }
+            Key::Property(p) => {
+                map.insert(p.to_cow().into_owned(), value.into());
+            }
+            _ => {
+                return Err(SetError::invalid_properties().with_property(key.clone().into_owned()));
+            }
+        }
+    }
+    Ok(map)
+}
+
+fn parse(json: serde_json::Map<String, serde_json::Value>) -> Result<Rule, SetError<P>> {
+    let rule: Rule = serde_json::from_value(serde_json::Value::Object(json)).map_err(|err| {
+        SetError::invalid_properties().with_description(format!("Not a valid rule: {err}"))
+    })?;
+    rule.validate().map_err(|invalid| {
+        let property = invalid.property.parse::<P>().unwrap_or(P::Name);
+        SetError::invalid_properties()
+            .with_property(property)
+            .with_description(invalid.reason)
+    })?;
+    Ok(rule)
+}
+
+fn forbidden(kind: Kind) -> SetError<P> {
+    SetError::forbidden().with_description(match kind {
+        Kind::Dlp => "Changing DLP rules needs the permission to change DLP rules.",
+        Kind::Transport => "Changing mail flow rules needs the permission to change them.",
+    })
+}
+
+fn rule_id(id: Id) -> Option<u32> {
+    u32::try_from(id.id()).ok()
+}
+
+/// `inbuxa:MailRule/get`: the rules the caller may see, in the order they
+/// run.
+pub async fn get(
+    server: &Server,
+    access_token: &AccessToken,
+    mut request: GetRequest<MailRule>,
+) -> trc::Result<GetResponse<MailRule>> {
+    server_level(access_token)?;
+    let properties = request.unwrap_properties(ALL);
+    let (ids, not_found) = request.unwrap_ids(server.core.jmap.get_max_objects)?;
+    let mut response = GetResponse {
+        account_id: request.account_id.into(),
+        state: None,
+        list: Vec::new(),
+        not_found,
+    };
+    let visible: Vec<Rule> = rules::all(server.store())
+        .await?
+        .into_iter()
+        .filter(|rule| can_see(access_token, rule.kind))
+        .collect();
+    match ids {
+        None => {
+            response.list = visible
+                .iter()
+                .map(|rule| to_value(rule, &properties))
+                .collect()
+        }
+        Some(ids) => {
+            for id in ids {
+                match rule_id(id).and_then(|id| visible.iter().find(|r| r.id == id)) {
+                    Some(rule) => response.list.push(to_value(rule, &properties)),
+                    None => response.push_not_found(id),
+                }
+            }
+        }
+    }
+    Ok(response)
+}
+
+/// `inbuxa:MailRule/set`: create, change or delete rules, each checked
+/// against the permissions for its kind (and, on a change of kind, both).
+pub async fn set(
+    server: &Server,
+    access_token: &AccessToken,
+    mut request: SetRequest<'_, MailRule>,
+) -> trc::Result<SetResponse<MailRule>> {
+    server_level(access_token)?;
+    let mut response = SetResponse::from_request(&request, server.core.jmap.set_max_objects)?;
+    let data = server.store();
+    let actor = server.audit_actor(access_token).await;
+
+    for (client_id, value) in request.unwrap_create() {
+        let rule = match client_json(value).and_then(parse) {
+            Ok(rule) => rule,
+            Err(error) => {
+                response.not_created.append(client_id, error);
+                continue;
+            }
+        };
+        if !can_change(access_token, rule.kind) {
+            response.not_created.append(client_id, forbidden(rule.kind));
+            continue;
+        }
+        let at = now();
+        let rule = Rule {
+            created_by: actor.name.clone(),
+            created_at: at,
+            updated_at: at,
+            ..rule
+        };
+        let id = rules::create(data, &rule).await?;
+        let mut out = Map::with_capacity(1);
+        out.insert_unchecked(
+            Key::Property(P::Id),
+            Value::Element(MailRuleValue::Id(Id::from(id))),
+        );
+        response.created.insert(client_id, Value::Object(out));
+    }
+
+    for (id, value) in request.unwrap_update().into_valid() {
+        let Some(current) = (match rule_id(id) {
+            Some(rule_id) => rules::get(data, rule_id).await?,
+            None => None,
+        }) else {
+            response.not_updated.append(id, SetError::not_found());
+            continue;
+        };
+        if !can_see(access_token, current.kind) {
+            response.not_updated.append(id, SetError::not_found());
+            continue;
+        }
+        if !can_change(access_token, current.kind) {
+            response.not_updated.append(id, forbidden(current.kind));
+            continue;
+        }
+        // The stored rule, with each property sent replacing its own
+        let mut json = match serde_json::to_value(&current) {
+            Ok(serde_json::Value::Object(map)) => map,
+            _ => serde_json::Map::new(),
+        };
+        let changes = match client_json(value) {
+            Ok(changes) => changes,
+            Err(error) => {
+                response.not_updated.append(id, error);
+                continue;
+            }
+        };
+        json.extend(changes);
+        let next = match parse(json) {
+            Ok(next) => next,
+            Err(error) => {
+                response.not_updated.append(id, error);
+                continue;
+            }
+        };
+        if next.kind != current.kind && !can_change(access_token, next.kind) {
+            response.not_updated.append(id, forbidden(next.kind));
+            continue;
+        }
+        let next = Rule {
+            id: current.id,
+            created_by: current.created_by.clone(),
+            created_at: current.created_at,
+            updated_at: now(),
+            ..next
+        };
+        if next != current {
+            rules::update(data, &next).await?;
+        }
+        response.updated.append(id, None);
+    }
+
+    for id in request.unwrap_destroy().into_valid() {
+        let Some(current) = (match rule_id(id) {
+            Some(rule_id) => rules::get(data, rule_id).await?,
+            None => None,
+        }) else {
+            response.not_destroyed.append(id, SetError::not_found());
+            continue;
+        };
+        if !can_see(access_token, current.kind) {
+            response.not_destroyed.append(id, SetError::not_found());
+            continue;
+        }
+        if !can_change(access_token, current.kind) {
+            response.not_destroyed.append(id, forbidden(current.kind));
+            continue;
+        }
+        rules::delete(data, current.id).await?;
+        response.destroyed.push(id);
+    }
+
+    Ok(response)
+}

crates/jmap/src/inbuxa/mod.rs

@@ -10,6 +10,7 @@
 pub mod access;
 pub mod account_lock;
 pub mod legal_hold;
+pub mod mail_rule;
 pub mod hold_export;
 pub mod hold_export_api;
 pub mod audit;

crates/registry/src/schema/enums.rs

@@ -1748,6 +1748,13 @@ pub enum Permission {
     SysLegalHoldExport = 672,
     // inbuxa: personal-data catalog, the data inventory and compliance overview
     SysComplianceGet = 673,
+    // inbuxa: DLP and mail flow rules
+    SysMailRuleGet = 674,
+    SysMailRuleUpdate = 675,
+    SysDlpPolicyGet = 676,
+    SysDlpPolicyUpdate = 677,
+    SysDlpReviewGet = 678,
+    SysDlpReviewUpdate = 679,
     SysAccountGet = 219,
     SysAccountCreate = 220,
     SysAccountUpdate = 221,

crates/registry/src/schema/enums_impl.rs

@@ -7091,6 +7091,12 @@ impl EnumImpl for Permission {
             b"sysLegalHoldUpdate" => Permission::SysLegalHoldUpdate,
             b"sysLegalHoldExport" => Permission::SysLegalHoldExport,
             b"sysComplianceGet" => Permission::SysComplianceGet,
+            b"sysMailRuleGet" => Permission::SysMailRuleGet,
+            b"sysMailRuleUpdate" => Permission::SysMailRuleUpdate,
+            b"sysDlpPolicyGet" => Permission::SysDlpPolicyGet,
+            b"sysDlpPolicyUpdate" => Permission::SysDlpPolicyUpdate,
+            b"sysDlpReviewGet" => Permission::SysDlpReviewGet,
+            b"sysDlpReviewUpdate" => Permission::SysDlpReviewUpdate,
             b"sysAccountGet" => Permission::SysAccountGet,
             b"sysAccountCreate" => Permission::SysAccountCreate,
             b"sysAccountUpdate" => Permission::SysAccountUpdate,
@@ -7781,6 +7787,12 @@ impl EnumImpl for Permission {
             Permission::SysLegalHoldUpdate => "sysLegalHoldUpdate",
             Permission::SysLegalHoldExport => "sysLegalHoldExport",
             Permission::SysComplianceGet => "sysComplianceGet",
+            Permission::SysMailRuleGet => "sysMailRuleGet",
+            Permission::SysMailRuleUpdate => "sysMailRuleUpdate",
+            Permission::SysDlpPolicyGet => "sysDlpPolicyGet",
+            Permission::SysDlpPolicyUpdate => "sysDlpPolicyUpdate",
+            Permission::SysDlpReviewGet => "sysDlpReviewGet",
+            Permission::SysDlpReviewUpdate => "sysDlpReviewUpdate",
             Permission::SysAccountGet => "sysAccountGet",
             Permission::SysAccountCreate => "sysAccountCreate",
             Permission::SysAccountUpdate => "sysAccountUpdate",
@@ -8464,6 +8476,12 @@ impl EnumImpl for Permission {
             671 => Some(Permission::SysLegalHoldUpdate),
             672 => Some(Permission::SysLegalHoldExport),
             673 => Some(Permission::SysComplianceGet),
+            674 => Some(Permission::SysMailRuleGet),
+            675 => Some(Permission::SysMailRuleUpdate),
+            676 => Some(Permission::SysDlpPolicyGet),
+            677 => Some(Permission::SysDlpPolicyUpdate),
+            678 => Some(Permission::SysDlpReviewGet),
+            679 => Some(Permission::SysDlpReviewUpdate),
             219 => Some(Permission::SysAccountGet),
             220 => Some(Permission::SysAccountCreate),
             221 => Some(Permission::SysAccountUpdate),
@@ -8908,7 +8926,7 @@ impl EnumImpl for Permission {
         }
     }
 
-    const COUNT: usize = 674;
+    const COUNT: usize = 680;
 }
 
 impl serde::Serialize for Permission {

crates/types/src/branding.rs

@@ -81,7 +81,7 @@ fn legacy_setting(name: &str, is_set: impl Fn(&str) -> bool) -> Option<String> {
 #[macro_export]
 macro_rules! brand_version {
     () => {
-        "2026.9.28.6"
+        "2026.9.28.5"
     };
 }
 

docs/spec/features/dlp-and-mail-flow-rules.md

@@ -139,6 +139,14 @@ DLP adds **detectors**. Each counts what it finds, and a rule sets a minimum
   either side, in the languages where the identifier is used ("passport",
   "Reisepass", "pasaporte"...).
 
+A check that about one random number in ten passes (Luhn, mod 10, mod 11) is
+too weak for a bare run of digits: invoice and phone numbers would match. So
+a checked identifier that is only digits (SSN, SIN, NHS, TFN, Medicare…)
+counts alone in the written form it's issued in (`536-22-1234`,
+`130 692 544`, `943 476 5919`), and as bare digits only beside a word. ABA
+routing numbers and NPIs are never written with separators, so they always
+need a word. (Refinement made while building phase 2, 2026-09-28.)
+
 The catalog (settled answer 6: the recognized, protected identifiers, not a
 chosen few). Each row is one table entry and one check function in
 `crates/features/src/mailflow/detectors/`:
@@ -157,10 +165,10 @@ chosen few). Each row is one table entry and one check function in
 | US | Social Security number | Checked | `AAA-GG-SSSS`, or nine digits with a word; never area 000, 666 or 9xx, group 00, serial 0000 |
 | US | ITIN | Checked | 9XX-GG-SSSS with the IRS's group ranges |
 | US | EIN | Needs a word | a valid IRS prefix and seven digits |
-| US | Bank routing number (ABA) | Checked | nine digits, a valid Federal Reserve prefix, the 3-7-1 checksum |
+| US | Bank routing number (ABA) | Needs a word | nine digits, a valid Federal Reserve prefix, the 3-7-1 checksum |
 | US | Driver's license | Needs a word | each state's published format |
 | US | Medicare Beneficiary Identifier | Checked | CMS's 11-character pattern and excluded letters |
-| US | National Provider Identifier | Checked | ten digits, Luhn over the `80840` prefix |
+| US | National Provider Identifier | Needs a word | ten digits, Luhn over the `80840` prefix |
 | US | DEA registration number | Checked | two letters, seven digits, DEA's check digit |
 | UK | National Insurance number | Checked | two letters (HMRC's excluded prefixes), six digits, A–D |
 | UK | NHS number | Checked | ten digits, mod 11 |

resources/privacy/catalog.toml

@@ -79,6 +79,21 @@ lockedAt = ["metadata"]
 lockedBy = ["identifier"]
 delegates = ["identifier"]
 
+[object."inbuxa:MailRule"]
+file = "inbuxa_mail_rule.rs"
+default = "none"
+whose = ["administrator", "holder", "correspondent"]
+where = ["data-store"]
+scope = "server"
+retention = "unbounded"
+[object."inbuxa:MailRule".properties]
+name = ["content"]
+description = ["content"]
+conditions = ["contact", "content"]
+exceptions = ["contact", "content"]
+actions = ["contact", "content"]
+createdBy = ["identifier"]
+
 [object."inbuxa:LegalHold"]
 file = "inbuxa_legal_hold.rs"
 default = "none"

resources/schema/schema.json.sha256

@@ -1 +1 @@
-k496pjVWlQ2p4bkZCh8agzaCKMLD4c3Z9WtoxpckYDU
+yF7PlBR3UBqxlabhW5zZ5WacQWsynG1wNYEiJVAl6w4

tests/src/system/mail_rules.rs

@@ -0,0 +1,201 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:MailRule` (dlp-and-mail-flow-rules spec, §2.2, §2.8): rules are
+//! stored, listed in the order they run, checked when written, kept apart
+//! by kind for permissions, and every change is audited.
+
+use crate::utils::{
+    account::Account,
+    server::{TestServer, TestServerBuilder},
+};
+use registry::schema::{
+    prelude::{ObjectType, Property},
+    structs::{CustomRoles, Role, UserRoles},
+};
+use registry::types::map::Map;
+use serde_json::{Value, json};
+
+const USING: &[&str] = &[
+    "urn:ietf:params:jmap:core",
+    "urn:inbuxa:jmap",
+    "urn:inbuxa:jmap:registry",
+];
+
+async fn call(account: &Account, method: &str, mut arguments: Value) -> (String, Value) {
+    if arguments.get("accountId").is_none() {
+        arguments["accountId"] = account.id_string().into();
+    }
+    let response = account.jmap_request(USING, json!([[method, arguments, "0"]])).await;
+    let call = response
+        .0
+        .pointer("/methodResponses/0")
+        .cloned()
+        .unwrap_or_else(|| panic!("{method}: {}", response.0));
+    (call[0].as_str().unwrap_or_default().to_string(), call[1].clone())
+}
+
+fn dlp_rule() -> Value {
+    json!({
+        "name": "Cards leaving",
+        "kind": "dlp",
+        "direction": "outgoing",
+        "priority": 10,
+        "conditions": [
+            {"type": "recipientOutside"},
+            {"type": "detected", "detectors": [{"id": "payment-card", "atLeast": 5}]}
+        ],
+        "actions": [{"type": "hold", "notice": "Held for review", "notifySender": true}]
+    })
+}
+
+fn transport_rule() -> Value {
+    json!({
+        "name": "Disclaimer",
+        "kind": "transport",
+        "direction": "outgoing",
+        "priority": 1,
+        "conditions": [{"type": "recipientOutside"}],
+        "actions": [{"type": "addDisclaimer", "text": "Sent by Example Co.", "position": "bottom"}]
+    })
+}
+
+async fn names(account: &Account) -> Vec<String> {
+    let (name, response) = call(account, "inbuxa:MailRule/get", json!({"ids": null})).await;
+    assert_eq!(name, "inbuxa:MailRule/get", "{response}");
+    response["list"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .map(|r| r["name"].as_str().unwrap().to_string())
+        .collect()
+}
+
+pub async fn test(test: &mut TestServer) {
+    println!("Running mail rule tests...");
+    let admin = test.account("[email protected]");
+
+    // Created, then listed in the order they run
+    let (_, response) = call(
+        &admin,
+        "inbuxa:MailRule/set",
+        json!({"create": {"d": dlp_rule(), "t": transport_rule()}}),
+    )
+    .await;
+    let dlp_id = response["created"]["d"]["id"]
+        .as_str()
+        .unwrap_or_else(|| panic!("DLP rule created: {response}"))
+        .to_string();
+    let transport_id = response["created"]["t"]["id"].as_str().unwrap().to_string();
+    assert_eq!(names(&admin).await, vec!["Disclaimer", "Cards leaving"]);
+
+    let (_, response) = call(&admin, "inbuxa:MailRule/get", json!({"ids": [dlp_id]})).await;
+    let rule = &response["list"][0];
+    assert_eq!(rule["conditions"][1]["detectors"][0]["atLeast"], 5, "{rule}");
+    assert_eq!(rule["actions"][0]["notifySender"], true);
+    assert_eq!(rule["createdBy"], "[email protected]");
+    assert!(rule["createdAt"].as_str().is_some_and(|d| d.ends_with('Z')), "{rule}");
+
+    // Checked when written
+    let mut inbound = dlp_rule();
+    inbound["direction"] = "incoming".into();
+    let mut unknown = dlp_rule();
+    unknown["conditions"][1]["detectors"][0]["id"] = "no-such-detector".into();
+    let (_, response) = call(
+        &admin,
+        "inbuxa:MailRule/set",
+        json!({"create": {"a": inbound, "b": unknown, "c": {"name": "x", "kind": "dlp"}}}),
+    )
+    .await;
+    assert_eq!(response["notCreated"]["a"]["properties"][0], "direction", "{response}");
+    assert!(
+        response["notCreated"]["b"]["description"].as_str().unwrap().contains("no-such-detector"),
+        "{response}"
+    );
+    assert!(response["notCreated"].get("c").is_some(), "{response}");
+
+    // Changed in place; what the server sets can't be sent
+    let (_, response) = call(
+        &admin,
+        "inbuxa:MailRule/set",
+        json!({"update": {
+            transport_id.as_str(): {"name": "Footer", "priority": 50},
+            dlp_id.as_str(): {"createdBy": "someone else"}
+        }}),
+    )
+    .await;
+    assert!(response["updated"].get(transport_id.as_str()).is_some(), "{response}");
+    assert_eq!(response["notUpdated"][dlp_id.as_str()]["properties"][0], "createdBy", "{response}");
+    assert_eq!(names(&admin).await, vec!["Cards leaving", "Footer"]);
+
+    // A compliance officer sees DLP rules, not mail flow rules, and changes
+    // neither (settled answer 4)
+    let mut officer_role = None;
+    for id in admin
+        .registry_query_ids(ObjectType::Role, Vec::<(&str, &str)>::new(), Vec::<&str>::new())
+        .await
+    {
+        let role = admin.registry_get::<Role>(id).await;
+        if role.description == "Compliance Officer" && role.member_tenant_id.is_none() {
+            officer_role = Some(id);
+        }
+    }
+    let officer = admin
+        .create_user_account("[email protected]", "officer-secret-7731", "Officer", &[], vec![])
+        .await;
+    admin
+        .registry_update_object(
+            ObjectType::Account,
+            officer.id(),
+            json!({Property::Roles: UserRoles::Custom(CustomRoles {
+                role_ids: Map::new(vec![officer_role.expect("the officer role")]),
+            })}),
+        )
+        .await;
+    assert_eq!(names(&officer).await, vec!["Cards leaving"]);
+    let (name, response) =
+        call(&officer, "inbuxa:MailRule/set", json!({"create": {"d": dlp_rule()}})).await;
+    assert_eq!(name, "error", "the officer created a DLP rule: {response}");
+
+    // Deleted
+    let (_, response) = call(
+        &admin,
+        "inbuxa:MailRule/set",
+        json!({"destroy": [transport_id]}),
+    )
+    .await;
+    assert_eq!(response["destroyed"][0], transport_id.as_str(), "{response}");
+    assert_eq!(names(&admin).await, vec!["Cards leaving"]);
+
+    // Every change is in the audit log
+    let (_, response) = call(
+        &admin,
+        "inbuxa:AuditEvent/query",
+        json!({"filter": {"targetKind": "inbuxa:MailRule"}, "calculateTotal": true}),
+    )
+    .await;
+    assert!(
+        response["total"].as_u64().unwrap_or(0) >= 4,
+        "creates, update and destroy audited: {response}"
+    );
+}
+
+#[ignore]
+#[tokio::test(flavor = "multi_thread")]
+pub async fn mail_rules_tests() {
+    let mut test = TestServerBuilder::new("mail_rules_tests")
+        .await
+        .with_default_listeners()
+        .await
+        .build()
+        .await;
+    let admin = test.create_admin_account("[email protected]").await;
+    test.insert_account(admin);
+    self::test(&mut test).await;
+    if test.is_reset() {
+        test.temp_dir.delete();
+    }
+}

tests/src/system/mod.rs

@@ -14,6 +14,7 @@ pub mod ai_explain;
 pub mod account_lock; // inbuxa: account lock with delegation
 pub mod legal_hold; // inbuxa: legal hold
 pub mod compliance; // inbuxa: the compliance roles
+pub mod mail_rules; // inbuxa: DLP and mail flow rules
 pub mod audit; // inbuxa: the audit log
 pub mod authorization;
 pub mod auto_reload; // inbuxa: registry writes apply at once