DLP: how long held mail waits is a setting

inbuxa:DlpSettings (singleton, urn:inbuxa:jmap): keepHeldDays, 1 to 90,
7 by default (settled answer 5 made it a setting). sysDlpPolicyGet reads
it, sysDlpPolicyUpdate changes it, server-level, audited by the request
layer. Each held message keeps the days it was given, and the sender's
notices say that number. Privacy catalog entry; spec §2.6 updated.

mail_rules_tests: 7 by default, 0 refused, 3 set and a message held
afterwards expires 3 days after it was held, the expiry notice says 3.

crates/features/src/mailflow/held.rs

@@ -25,14 +25,42 @@ use trc::AddContext;
 
 const FEATURE: u8 = b'R';
 const KIND_HELD: u8 = b'h';
+const KIND_SETTINGS: u8 = b's';
 
 /// How far off a held message's release is set: a century, so it never
 /// comes due on its own.
 pub const HOLD_SECONDS: u64 = 100 * 365 * 24 * 60 * 60;
 
-/// How long unreviewed mail waits before it's rejected (settled answer 5).
+/// How long unreviewed mail waits before it's rejected, unless the setting
+/// says otherwise (settled answer 5).
 pub const KEEP_DAYS: u64 = 7;
 
+/// `inbuxa:DlpSettings`: how many days held mail waits for a reviewer.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Settings {
+    pub keep_held_days: u64,
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        Settings {
+            keep_held_days: KEEP_DAYS,
+        }
+    }
+}
+
+impl Settings {
+    /// The property at fault and why, or fine.
+    pub fn check(&self) -> Result<(), (&'static str, &'static str)> {
+        if (1..=90).contains(&self.keep_held_days) {
+            Ok(())
+        } else {
+            Err(("keepHeldDays", "must be from 1 to 90 days"))
+        }
+    }
+}
+
 /// A rule that held the message, with its notice.
 #[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
 pub struct HeldRule {
@@ -59,6 +87,13 @@ pub struct Held {
     /// Seconds since the epoch.
     pub held_at: u64,
     pub expires_at: u64,
+    /// The days it was given, for what the sender is told.
+    #[serde(default = "default_keep_days")]
+    pub keep_days: u64,
+}
+
+fn default_keep_days() -> u64 {
+    KEEP_DAYS
 }
 
 impl Held {
@@ -106,6 +141,31 @@ fn key(queue_id: u64) -> ValueKey<ValueClass> {
     ValueKey::from(class(queue_id))
 }
 
+fn settings_class() -> ValueClass {
+    ValueClass::Any(AnyClass {
+        subspace: SUBSPACE_INBUXA,
+        key: vec![FEATURE, KIND_SETTINGS],
+    })
+}
+
+pub async fn settings(data: &Store) -> trc::Result<Settings> {
+    Ok(data
+        .get_value::<Json<Settings>>(ValueKey::from(settings_class()))
+        .await
+        .caused_by(trc::location!())?
+        .map(|Json(settings)| settings)
+        .unwrap_or_default())
+}
+
+pub async fn set_settings(data: &Store, settings: &Settings) -> trc::Result<()> {
+    let mut batch = BatchBuilder::new();
+    batch.set(settings_class(), Json(settings).serialize()?);
+    data.write(batch.build_all())
+        .await
+        .caused_by(trc::location!())?;
+    Ok(())
+}
+
 pub async fn get(data: &Store, queue_id: u64) -> trc::Result<Option<Held>> {
     Ok(data
         .get_value::<Json<Held>>(key(queue_id))
@@ -172,6 +232,7 @@ mod tests {
             counts: vec![("payment-card".into(), 5)],
             held_at: 1_000,
             expires_at: 1_000 + KEEP_DAYS * 86_400,
+            keep_days: KEEP_DAYS,
         };
         let json = serde_json::to_value(&held).unwrap();
         assert_eq!(json["heldAt"], 1_000);
@@ -180,4 +241,13 @@ mod tests {
         assert!(held.is_expired(1_000 + KEEP_DAYS * 86_400));
         assert!(HOLD_SECONDS > 90 * 365 * 86_400);
     }
+
+    #[test]
+    fn settings_range() {
+        assert_eq!(Settings::default().keep_held_days, 7);
+        assert!(Settings { keep_held_days: 1 }.check().is_ok());
+        assert!(Settings { keep_held_days: 90 }.check().is_ok());
+        assert!(Settings { keep_held_days: 0 }.check().is_err());
+        assert!(Settings { keep_held_days: 91 }.check().is_err());
+    }
 }

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

@@ -0,0 +1,153 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:DlpSettings/get` and `/set` under `urn:inbuxa:jmap`: the DLP
+//! settings singleton (dlp-and-mail-flow-rules spec, §2.6): how many days
+//! held mail waits for a reviewer before it goes back to the sender.
+
+use crate::object::{AnyId, JmapObject, JmapObjectId};
+use jmap_tools::{Element, Key, Property};
+use std::{borrow::Cow, str::FromStr};
+use types::id::Id;
+
+#[derive(Debug, Clone, Default)]
+pub struct DlpSettings;
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum DlpSettingsProperty {
+    Id,
+    KeepHeldDays,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum DlpSettingsValue {
+    Id(Id),
+}
+
+impl Property for DlpSettingsProperty {
+    fn try_parse(_: Option<&Key<'_, Self>>, value: &str) -> Option<Self> {
+        DlpSettingsProperty::parse(value)
+    }
+
+    fn to_cow(&self) -> Cow<'static, str> {
+        match self {
+            DlpSettingsProperty::Id => "id",
+            DlpSettingsProperty::KeepHeldDays => "keepHeldDays",
+        }
+        .into()
+    }
+}
+
+impl DlpSettingsProperty {
+    fn parse(value: &str) -> Option<Self> {
+        hashify::tiny_map!(value.as_bytes(),
+            b"id" => DlpSettingsProperty::Id,
+            b"keepHeldDays" => DlpSettingsProperty::KeepHeldDays,
+        )
+    }
+}
+
+impl FromStr for DlpSettingsProperty {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        DlpSettingsProperty::parse(s).ok_or(())
+    }
+}
+
+impl Element for DlpSettingsValue {
+    type Property = DlpSettingsProperty;
+
+    fn try_parse<P>(key: &Key<'_, Self::Property>, value: &str) -> Option<Self> {
+        match key {
+            Key::Property(DlpSettingsProperty::Id) => {
+                Id::from_str(value).ok().map(DlpSettingsValue::Id)
+            }
+            _ => None,
+        }
+    }
+
+    fn to_cow(&self) -> Cow<'static, str> {
+        match self {
+            DlpSettingsValue::Id(id) => id.to_string().into(),
+        }
+    }
+}
+
+impl JmapObject for DlpSettings {
+    type Property = DlpSettingsProperty;
+
+    type Element = DlpSettingsValue;
+
+    type Id = Id;
+
+    type Filter = ();
+
+    type Comparator = ();
+
+    type GetArguments = ();
+
+    type SetArguments<'de> = ();
+
+    type QueryArguments = ();
+
+    type CopyArguments = ();
+
+    type ParseArguments = ();
+
+    const ID_PROPERTY: Self::Property = DlpSettingsProperty::Id;
+}
+
+impl From<Id> for DlpSettingsValue {
+    fn from(id: Id) -> Self {
+        DlpSettingsValue::Id(id)
+    }
+}
+
+impl JmapObjectId for DlpSettingsValue {
+    fn as_id(&self) -> Option<Id> {
+        match self {
+            DlpSettingsValue::Id(id) => Some(*id),
+        }
+    }
+
+    fn as_any_id(&self) -> Option<AnyId> {
+        match self {
+            DlpSettingsValue::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 = DlpSettingsValue::Id(id);
+            true
+        } else {
+            false
+        }
+    }
+}
+
+impl JmapObjectId for DlpSettingsProperty {
+    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

@@ -24,6 +24,7 @@ pub mod fastmail_masked_email; // inbuxa: masked email
 pub mod inbuxa_account_lock; // inbuxa: account lock with delegation
 pub mod inbuxa_ai_limits; // inbuxa: AI spam classification
 pub mod inbuxa_log_settings; // inbuxa: personal-data catalog, D1
+pub mod inbuxa_dlp_settings; // inbuxa: DLP settings
 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

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

@@ -64,6 +64,9 @@ impl Response<'_> {
                         GetResponseMethod::LogSettings(response) => {
                             response.eval_jptr(path, &mut results)
                         }
+                        GetResponseMethod::DlpSettings(response) => {
+                            response.eval_jptr(path, &mut results)
+                        }
                         GetResponseMethod::DataInventory(response) => {
                             response.eval_jptr(path, &mut results)
                         }

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

@@ -47,6 +47,7 @@ impl Response<'_> {
                 GetRequestMethod::DeletedAccount(request) => request.resolve_references(self)?,
                 GetRequestMethod::AiLimits(request) => request.resolve_references(self)?,
                 GetRequestMethod::LogSettings(request) => request.resolve_references(self)?,
+                GetRequestMethod::DlpSettings(request) => request.resolve_references(self)?,
                 GetRequestMethod::DataInventory(request) => request.resolve_references(self)?,
                 GetRequestMethod::InventorySnapshot(request) => request.resolve_references(self)?,
                 GetRequestMethod::AuditEvent(request) => request.resolve_references(self)?,
@@ -106,6 +107,9 @@ impl Response<'_> {
                 SetRequestMethod::LogSettings(request) => {
                     request.resolve_references(self, 1, false)?
                 }
+                SetRequestMethod::DlpSettings(request) => {
+                    request.resolve_references(self, 1, false)?
+                }
                 SetRequestMethod::Explanation(request) => {
                     request.resolve_references(self, 1, false)?
                 }

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

@@ -50,6 +50,7 @@ pub enum MethodObject {
     // inbuxa: AI call limits
     AiLimits,
     LogSettings,
+    DlpSettings,
     DataInventory,
     InventorySnapshot,
     // inbuxa: "Explain this" with the local model
@@ -96,6 +97,7 @@ impl MethodObject {
             MethodObject::DeletedAccount => Capability::Inbuxa,
             MethodObject::AiLimits => Capability::Inbuxa,
             MethodObject::LogSettings => Capability::Inbuxa,
+            MethodObject::DlpSettings => Capability::Inbuxa,
             MethodObject::DataInventory => Capability::Inbuxa,
             MethodObject::InventorySnapshot => Capability::Inbuxa,
             MethodObject::Explanation => Capability::Inbuxa,
@@ -288,9 +290,11 @@ impl MethodName {
             (MethodFunction::Get, MethodObject::AiLimits) => "inbuxa:AiLimits/get",
             (MethodFunction::Set, MethodObject::AiLimits) => "inbuxa:AiLimits/set",
             (MethodFunction::Get, MethodObject::LogSettings) => "inbuxa:LogSettings/get",
+            (MethodFunction::Get, MethodObject::DlpSettings) => "inbuxa:DlpSettings/get",
             (MethodFunction::Get, MethodObject::DataInventory) => "inbuxa:DataInventory/get",
             (MethodFunction::Get, MethodObject::InventorySnapshot) => "inbuxa:InventorySnapshot/get",
             (MethodFunction::Set, MethodObject::LogSettings) => "inbuxa:LogSettings/set",
+            (MethodFunction::Set, MethodObject::DlpSettings) => "inbuxa:DlpSettings/set",
             (MethodFunction::Set, MethodObject::Explanation) => "inbuxa:Explanation/set",
             (MethodFunction::Get, MethodObject::AuditEvent) => "inbuxa:AuditEvent/get",
             (MethodFunction::Query, MethodObject::AuditEvent) => "inbuxa:AuditEvent/query",
@@ -444,9 +448,11 @@ impl MethodName {
             "inbuxa:AiLimits/get" => (MethodObject::AiLimits, MethodFunction::Get),
             "inbuxa:AiLimits/set" => (MethodObject::AiLimits, MethodFunction::Set),
             "inbuxa:LogSettings/get" => (MethodObject::LogSettings, MethodFunction::Get),
+            "inbuxa:DlpSettings/get" => (MethodObject::DlpSettings, MethodFunction::Get),
             "inbuxa:DataInventory/get" => (MethodObject::DataInventory, MethodFunction::Get),
             "inbuxa:InventorySnapshot/get" => (MethodObject::InventorySnapshot, MethodFunction::Get),
             "inbuxa:LogSettings/set" => (MethodObject::LogSettings, MethodFunction::Set),
+            "inbuxa:DlpSettings/set" => (MethodObject::DlpSettings, MethodFunction::Set),
             "inbuxa:Explanation/set" => (MethodObject::Explanation, MethodFunction::Set),
             "inbuxa:AuditEvent/get" => (MethodObject::AuditEvent, MethodFunction::Get),
             "inbuxa:AuditEvent/query" => (MethodObject::AuditEvent, MethodFunction::Query),
@@ -522,6 +528,7 @@ impl Display for MethodObject {
             MethodObject::DeletedAccount => "inbuxa:DeletedAccount",
             MethodObject::AiLimits => "inbuxa:AiLimits",
             MethodObject::LogSettings => "inbuxa:LogSettings",
+            MethodObject::DlpSettings => "inbuxa:DlpSettings",
             MethodObject::DataInventory => "inbuxa:DataInventory",
             MethodObject::InventorySnapshot => "inbuxa:InventorySnapshot",
             MethodObject::Explanation => "inbuxa:Explanation",

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

@@ -117,6 +117,7 @@ pub enum GetRequestMethod {
     DeletedAccount(Box<GetRequest<crate::object::inbuxa_deleted_account::DeletedAccount>>),
     AiLimits(Box<GetRequest<crate::object::inbuxa_ai_limits::AiLimits>>),
     LogSettings(Box<GetRequest<crate::object::inbuxa_log_settings::LogSettings>>),
+    DlpSettings(Box<GetRequest<crate::object::inbuxa_dlp_settings::DlpSettings>>),
     DataInventory(Box<GetRequest<crate::object::inbuxa_data_inventory::DataInventory>>),
     InventorySnapshot(Box<GetRequest<crate::object::inbuxa_inventory_snapshot::InventorySnapshot>>),
     AuditEvent(Box<GetRequest<crate::object::inbuxa_audit::AuditEvent>>),
@@ -154,6 +155,7 @@ pub enum SetRequestMethod<'x> {
     DeletedAccount(Box<SetRequest<'x, crate::object::inbuxa_deleted_account::DeletedAccount>>),
     AiLimits(Box<SetRequest<'x, crate::object::inbuxa_ai_limits::AiLimits>>),
     LogSettings(Box<SetRequest<'x, crate::object::inbuxa_log_settings::LogSettings>>),
+    DlpSettings(Box<SetRequest<'x, crate::object::inbuxa_dlp_settings::DlpSettings>>),
     Explanation(Box<SetRequest<'x, crate::object::inbuxa_explanation::Explanation>>),
     AuditSettings(Box<SetRequest<'x, crate::object::inbuxa_audit::AuditSettings>>),
     AuditExport(Box<SetRequest<'x, crate::object::inbuxa_audit::AuditExport>>),

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

@@ -176,6 +176,13 @@ impl<'de> Visitor<'de> for CallVisitor {
                     return Err(de::Error::invalid_length(1, &self));
                 }
             },
+            (MethodFunction::Get, MethodObject::DlpSettings) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::DlpSettings(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
             (MethodFunction::Get, MethodObject::DataInventory) => match seq.next_element() {
                 Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::DataInventory(value)),
                 Err(err) => RequestMethod::invalid(err),
@@ -378,6 +385,13 @@ impl<'de> Visitor<'de> for CallVisitor {
                     return Err(de::Error::invalid_length(1, &self));
                 }
             },
+            (MethodFunction::Set, MethodObject::DlpSettings) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Set(SetRequestMethod::DlpSettings(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
             (MethodFunction::Set, MethodObject::Explanation) => match seq.next_element() {
                 Ok(Some(value)) => RequestMethod::Set(SetRequestMethod::Explanation(value)),
                 Err(err) => RequestMethod::invalid(err),

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

@@ -104,6 +104,7 @@ pub enum GetResponseMethod {
     DeletedAccount(GetResponse<crate::object::inbuxa_deleted_account::DeletedAccount>),
     AiLimits(GetResponse<crate::object::inbuxa_ai_limits::AiLimits>),
     LogSettings(GetResponse<crate::object::inbuxa_log_settings::LogSettings>),
+    DlpSettings(GetResponse<crate::object::inbuxa_dlp_settings::DlpSettings>),
     DataInventory(GetResponse<crate::object::inbuxa_data_inventory::DataInventory>),
     InventorySnapshot(GetResponse<crate::object::inbuxa_inventory_snapshot::InventorySnapshot>),
     AuditEvent(GetResponse<crate::object::inbuxa_audit::AuditEvent>),
@@ -142,6 +143,7 @@ pub enum SetResponseMethod {
     DeletedAccount(Box<SetResponse<crate::object::inbuxa_deleted_account::DeletedAccount>>),
     AiLimits(Box<SetResponse<crate::object::inbuxa_ai_limits::AiLimits>>),
     LogSettings(Box<SetResponse<crate::object::inbuxa_log_settings::LogSettings>>),
+    DlpSettings(Box<SetResponse<crate::object::inbuxa_dlp_settings::DlpSettings>>),
     AuditSettings(Box<SetResponse<crate::object::inbuxa_audit::AuditSettings>>),
     AuditExport(Box<SetResponse<crate::object::inbuxa_audit::AuditExport>>),
     AuditVerification(Box<SetResponse<crate::object::inbuxa_audit::AuditVerification>>),
@@ -363,6 +365,12 @@ impl<'x> From<GetResponse<crate::object::inbuxa_log_settings::LogSettings>> for
     }
 }
 
+impl<'x> From<GetResponse<crate::object::inbuxa_dlp_settings::DlpSettings>> for ResponseMethod<'x> {
+    fn from(value: GetResponse<crate::object::inbuxa_dlp_settings::DlpSettings>) -> Self {
+        ResponseMethod::Get(GetResponseMethod::DlpSettings(value))
+    }
+}
+
 impl<'x> From<GetResponse<crate::object::inbuxa_data_inventory::DataInventory>> for ResponseMethod<'x> {
     fn from(value: GetResponse<crate::object::inbuxa_data_inventory::DataInventory>) -> Self {
         ResponseMethod::Get(GetResponseMethod::DataInventory(value))
@@ -387,6 +395,12 @@ impl<'x> From<SetResponse<crate::object::inbuxa_log_settings::LogSettings>> for
     }
 }
 
+impl<'x> From<SetResponse<crate::object::inbuxa_dlp_settings::DlpSettings>> for ResponseMethod<'x> {
+    fn from(value: SetResponse<crate::object::inbuxa_dlp_settings::DlpSettings>) -> Self {
+        ResponseMethod::Set(SetResponseMethod::DlpSettings(Box::new(value)))
+    }
+}
+
 impl<'x> From<SetResponse<crate::object::inbuxa_explanation::Explanation>> for ResponseMethod<'x> {
     fn from(value: SetResponse<crate::object::inbuxa_explanation::Explanation>) -> Self {
         ResponseMethod::Set(SetResponseMethod::Explanation(Box::new(value)))

crates/jmap/src/api/auth.rs

@@ -92,6 +92,7 @@ impl JmapAuthorization for AccessToken {
                 GetRequestMethod::AiLimits(_) => Permission::SysSpamLlmGet,
                 // inbuxa: log file retention, with the tracers' permissions
                 GetRequestMethod::LogSettings(_) => Permission::SysTracerGet,
+                GetRequestMethod::DlpSettings(_) => Permission::SysDlpPolicyGet,
                 // inbuxa: personal-data catalog, the inventory and its history
                 GetRequestMethod::DataInventory(_) | GetRequestMethod::InventorySnapshot(_) => {
                     Permission::SysComplianceGet
@@ -227,6 +228,13 @@ impl JmapAuthorization for AccessToken {
                         Permission::SysTracerUpdate,
                         Permission::SysTracerUpdate,
                     ),
+                    SetRequestMethod::DlpSettings(s) => validate_set(
+                        s,
+                        self,
+                        Permission::SysDlpPolicyUpdate,
+                        Permission::SysDlpPolicyUpdate,
+                        Permission::SysDlpPolicyUpdate,
+                    ),
                     // inbuxa: the audit log (AU-7, AU-9, AU-11)
                     SetRequestMethod::AuditSettings(s) => validate_set(
                         s,
@@ -430,6 +438,7 @@ impl JmapAuthorization for AccessToken {
                 | MethodObject::DeletedAccount
                 | MethodObject::AiLimits
                 | MethodObject::LogSettings
+                | MethodObject::DlpSettings
                 | MethodObject::DataInventory
                 | MethodObject::InventorySnapshot
                 | MethodObject::Explanation

crates/jmap/src/api/request.rs

@@ -264,6 +264,9 @@ impl RequestHandler for Server {
                                     SetResponseMethod::LogSettings(set_response) => {
                                         set_response.update_created_ids(&mut response);
                                     }
+                                    SetResponseMethod::DlpSettings(set_response) => {
+                                        set_response.update_created_ids(&mut response);
+                                    }
                                     SetResponseMethod::AuditSettings(set_response) => {
                                         set_response.update_created_ids(&mut response);
                                     }
@@ -461,6 +464,13 @@ impl RequestHandler for Server {
                         .await?
                         .into()
                 }
+                // inbuxa: inbuxa:DlpSettings/get
+                GetRequestMethod::DlpSettings(mut req) => {
+                    resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
+                    crate::inbuxa::dlp_settings::get(self, access_token, *req)
+                        .await?
+                        .into()
+                }
                 // inbuxa: inbuxa:DataInventory/get
                 GetRequestMethod::DataInventory(mut req) => {
                     resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
@@ -826,6 +836,23 @@ impl RequestHandler for Server {
                     .await?
                     .into()
                 }
+                // inbuxa: inbuxa:DlpSettings/set
+                SetRequestMethod::DlpSettings(mut req) => {
+                    resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
+                    // inbuxa: AU-1.2, AU-3
+                    crate::inbuxa::audit::recorded(
+                        self,
+                        access_token,
+                        session,
+                        &method_name.obj.to_string(),
+                        None,
+                        None,
+                        *req,
+                        |req| Box::pin(crate::inbuxa::dlp_settings::set(self, access_token, req)),
+                    )
+                    .await?
+                    .into()
+                }
                 // inbuxa: the audit log (AU-7, AU-11, AU-6)
                 SetRequestMethod::AuditSettings(mut req) => {
                     resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;

crates/jmap/src/changes/get.rs

@@ -419,6 +419,7 @@ impl IntermediateChangesResponse {
             | MethodObject::DeletedAccount
             | MethodObject::AiLimits
             | MethodObject::LogSettings
+            | MethodObject::DlpSettings
             | MethodObject::DataInventory
             | MethodObject::InventorySnapshot
             | MethodObject::Explanation

crates/jmap/src/inbuxa/dlp_settings.rs

@@ -0,0 +1,154 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:DlpSettings/get` and `/set`: how many days held mail waits for a
+//! reviewer (dlp-and-mail-flow-rules spec, §2.6), 1 to 90, 7 by default.
+//! Server-level, like the rules; applies to mail held from then on.
+
+use common::{Server, auth::AccessToken};
+use inbuxa_features::mailflow::held::{self, Settings};
+use jmap_proto::{
+    error::set::SetError,
+    method::{
+        get::{GetRequest, GetResponse},
+        set::{SetRequest, SetResponse},
+    },
+    object::inbuxa_dlp_settings::{DlpSettings, DlpSettingsProperty as P, DlpSettingsValue},
+    request::IntoValid,
+};
+use jmap_tools::{Key, Map, Value};
+use types::id::Id;
+
+type LValue = Value<'static, P, DlpSettingsValue>;
+
+const ALL: &[P] = &[P::Id, P::KeepHeldDays];
+
+fn assert_server_level(access_token: &AccessToken) -> trc::Result<()> {
+    if access_token.tenant_id().is_some() {
+        Err(trc::JmapEvent::Forbidden
+            .into_err()
+            .details("DLP settings are server-level."))
+    } else {
+        Ok(())
+    }
+}
+
+fn to_value(settings: &Settings, properties: &[P]) -> LValue {
+    let mut out = Map::with_capacity(properties.len());
+    for property in properties {
+        let value = match property {
+            P::Id => Value::Element(DlpSettingsValue::Id(Id::singleton())),
+            P::KeepHeldDays => Value::Number(settings.keep_held_days.into()),
+        };
+        out.insert_unchecked(Key::Property(property.clone()), value);
+    }
+    Value::Object(out)
+}
+
+/// `inbuxa:DlpSettings/get`.
+pub async fn get(
+    server: &Server,
+    access_token: &AccessToken,
+    mut request: GetRequest<DlpSettings>,
+) -> trc::Result<GetResponse<DlpSettings>> {
+    assert_server_level(access_token)?;
+    let properties = request.unwrap_properties(ALL);
+    let (ids, not_found) = request.unwrap_ids(1)?;
+    let mut response = GetResponse {
+        account_id: request.account_id.into(),
+        state: None,
+        list: Vec::new(),
+        not_found,
+    };
+    let settings = held::settings(server.store()).await?;
+    match ids {
+        None => response.list.push(to_value(&settings, &properties)),
+        Some(ids) => {
+            for id in ids {
+                if id.is_singleton() {
+                    response.list.push(to_value(&settings, &properties));
+                } else {
+                    response.push_not_found(id);
+                }
+            }
+        }
+    }
+    Ok(response)
+}
+
+fn apply(
+    settings: &mut Settings,
+    property: &P,
+    value: &Value<'_, P, DlpSettingsValue>,
+) -> Result<(), String> {
+    match property {
+        P::KeepHeldDays => {
+            settings.keep_held_days = value
+                .as_u64()
+                .ok_or_else(|| "must be a whole number of days".to_string())?
+        }
+        P::Id => return Err("is immutable".to_string()),
+    }
+    Ok(())
+}
+
+/// `inbuxa:DlpSettings/set`: updates the singleton.
+pub async fn set(
+    server: &Server,
+    access_token: &AccessToken,
+    mut request: SetRequest<'_, DlpSettings>,
+) -> trc::Result<SetResponse<DlpSettings>> {
+    assert_server_level(access_token)?;
+    let mut response = SetResponse::from_request(&request, server.core.jmap.set_max_objects)?;
+    for (client_id, _) in request.unwrap_create() {
+        response
+            .not_created
+            .append(client_id, SetError::singleton());
+    }
+    for id in request.unwrap_destroy().into_valid() {
+        response.not_destroyed.append(id, SetError::singleton());
+    }
+    let data = server.store();
+    for (id, value) in request.unwrap_update().into_valid() {
+        if !id.is_singleton() {
+            response.not_updated.append(id, SetError::not_found());
+            continue;
+        }
+        let mut settings = held::settings(data).await?;
+        let mut error = None;
+        for (key, value) in value.into_expanded_object() {
+            let Key::Property(property) = &key else {
+                error = Some(SetError::invalid_properties().with_property(key.into_owned()));
+                break;
+            };
+            if let Err(why) = apply(&mut settings, property, &value) {
+                error = Some(
+                    SetError::invalid_properties()
+                        .with_property(property.clone())
+                        .with_description(why),
+                );
+                break;
+            }
+        }
+        if error.is_none()
+            && let Err((property, why)) = settings.check()
+        {
+            error = Some(
+                SetError::invalid_properties()
+                    .with_property(property.parse::<P>().unwrap_or(P::Id))
+                    .with_description(format!("{property} {why}.")),
+            );
+        }
+        match error {
+            Some(error) => response.not_updated.append(id, error),
+            None => {
+                held::set_settings(data, &settings).await?;
+                response.updated.append(id, None);
+            }
+        }
+    }
+    Ok(response)
+}

crates/jmap/src/inbuxa/mod.rs

@@ -12,6 +12,7 @@ pub mod account_lock;
 pub mod legal_hold;
 pub mod mail_rule;
 pub mod held_message;
+pub mod dlp_settings;
 pub mod hold_export;
 pub mod hold_export_api;
 pub mod audit;

crates/smtp/src/inbound/mailflow.rs

@@ -478,6 +478,9 @@ impl<T: SessionStream> Session<T> {
         size: u64,
     ) {
         let at = store::write::now();
+        let keep_days = held::settings(self.server.store())
+            .await
+            .map_or(KEEP_DAYS, |s| s.keep_held_days);
         let account = self.data.authenticated_as.as_ref();
         let record = Held {
             queue_id,
@@ -490,7 +493,8 @@ impl<T: SessionStream> Session<T> {
             rules: draft.rules,
             counts: draft.counts,
             held_at: at,
-            expires_at: at + KEEP_DAYS * 86_400,
+            expires_at: at + keep_days * 86_400,
+            keep_days,
         };
         if let Err(err) = held::create(self.server.store(), &record).await {
             trc::error!(

crates/smtp/src/queue/held.rs

@@ -24,7 +24,7 @@ use common::{
 };
 use inbuxa_features::{
     audit::{Action, Actor, Outcome, Record, Target},
-    mailflow::held::{self, HOLD_SECONDS, Held, KEEP_DAYS},
+    mailflow::held::{self, HOLD_SECONDS, Held},
 };
 use mail_builder::{
     MessageBuilder,
@@ -83,7 +83,8 @@ pub async fn reject(server: &Server, record: &Held, note: Option<&str>) -> trc::
     match note {
         Some(note) => text.push_str(&format!("\r\nThe reviewer's note: {note}\r\n")),
         None => text.push_str(&format!(
-            "\r\nNobody reviewed it within {KEEP_DAYS} days, so it was returned.\r\n"
+            "\r\nNobody reviewed it within {} days, so it was returned.\r\n",
+            record.keep_days
         )),
     }
     notify(
@@ -107,9 +108,10 @@ pub async fn notify_held(server: &Server, record: &Held) {
         .join(" ");
     let text = format!(
         "Your message \"{}\" to {} is held for review under this server's rules: {notices}\r\n\r\n\
-         It will be sent if a reviewer releases it, and returned otherwise within {KEEP_DAYS} days.\r\n",
+         It will be sent if a reviewer releases it, and returned otherwise within {} days.\r\n",
         record.subject,
         record.recipients.join(", "),
+        record.keep_days,
     );
     notify(
         server,
@@ -166,7 +168,8 @@ pub async fn expire(server: &Server) -> trc::Result<usize> {
                 },
                 changes: vec![],
                 details: Some(format!(
-                    "Rejected: nobody reviewed it within {KEEP_DAYS} days; the sender was told"
+                    "Rejected: nobody reviewed it within {} days; the sender was told",
+                    record.keep_days
                 )),
                 reason: None,
                 outcome: Outcome::success(),

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

@@ -304,8 +304,9 @@ held mail, so what's released is what would have gone out. The daily
 clean-up rejects what's past its 7 days (recorded as the server's doing).
 `preview` returns the text (64 KB) only when asked for, and each read is
 recorded as `blobAccess`. Emails › Queue refuses to change or delete held
-mail, and the sender can't unsend it. The 7 days is a constant for now; a
-setting comes with the console page.
+mail, and the sender can't unsend it. How many days held mail waits is
+`inbuxa:DlpSettings.keepHeldDays`, 1 to 90, 7 by default; each held message
+keeps the days it was given.
 
 ### 2.7 What's recorded
 

resources/privacy/catalog.toml

@@ -79,6 +79,10 @@ lockedAt = ["metadata"]
 lockedBy = ["identifier"]
 delegates = ["identifier"]
 
+[object."inbuxa:DlpSettings"]
+file = "inbuxa_dlp_settings.rs"
+default = "none"
+
 [object."inbuxa:HeldMessage"]
 file = "inbuxa_held_message.rs"
 default = "none"

tests/src/system/mail_rules.rs

@@ -19,6 +19,7 @@ use registry::schema::{
 };
 use registry::types::map::Map;
 use serde_json::{Value, json};
+use std::str::FromStr;
 
 const USING: &[&str] = &[
     "urn:ietf:params:jmap:core",
@@ -817,6 +818,26 @@ pub async fn hold(test: &mut TestServer) {
         .as_str()
         .unwrap_or_else(|| panic!("{response}"))
         .to_string();
+    // How long held mail waits: 7 days unless set, from 1 to 90
+    let (_, response) = call(&admin, "inbuxa:DlpSettings/get", json!({"ids": null})).await;
+    assert_eq!(response["list"][0]["keepHeldDays"], 7, "{response}");
+    let (_, response) = call(
+        &admin,
+        "inbuxa:DlpSettings/set",
+        json!({"update": {"singleton": {"keepHeldDays": 0}}}),
+    )
+    .await;
+    assert!(
+        response["notUpdated"].get("singleton").is_some(),
+        "{response}"
+    );
+    let (_, response) = call(
+        &admin,
+        "inbuxa:DlpSettings/set",
+        json!({"update": {"singleton": {"keepHeldDays": 3}}}),
+    )
+    .await;
+    assert!(response["updated"].get("singleton").is_some(), "{response}");
     let body = "hold-me: card 4242 4242 4242 4242";
 
     // Accepted, held, listed
@@ -844,6 +865,9 @@ pub async fn hold(test: &mut TestServer) {
     assert_eq!(list[0]["sender"], "[email protected]");
     assert_eq!(list[0]["subject"], "Held one");
     assert_eq!(list[0]["rules"][0]["name"], "Hold cards");
+    let span = chrono_seconds(list[0]["expiresAt"].as_str().unwrap())
+        - chrono_seconds(list[0]["heldAt"].as_str().unwrap());
+    assert_eq!(span, 3 * 86_400, "held for the days set");
     assert_eq!(
         list[0]["counts"],
         json!([{"detector": "words", "count": 1}, {"detector": "payment-card", "count": 1}])
@@ -1057,7 +1081,7 @@ pub async fn hold(test: &mut TestServer) {
     );
     let notice = received(&sender, "Not sent: Held three", "X-Flow", Some(&mailbox)).await;
     assert!(
-        notice[0].1.contains("Nobody reviewed it within 7 days"),
+        notice[0].1.contains("Nobody reviewed it within 3 days"),
         "{notice:?}"
     );
     let (_, response) = call(
@@ -1075,6 +1099,13 @@ pub async fn hold(test: &mut TestServer) {
     call(&admin, "inbuxa:MailRule/set", json!({"destroy": [rule]})).await;
 }
 
+/// Seconds since the epoch of a UTC date the server wrote.
+fn chrono_seconds(date: &str) -> i64 {
+    jmap_proto::types::date::UTCDate::from_str(date)
+        .map(|d| d.timestamp())
+        .unwrap_or_default()
+}
+
 /// Subjects in `account` matching `text` right now, not in `drafts`.
 async fn received_now(account: &Account, text: &str, drafts: &str) -> Vec<String> {
     let (_, response) = call(