crates/features/src/mailflow/held.rs

@@ -0,0 +1,183 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! Mail held for review (dlp-and-mail-flow-rules spec, §2.6).
+//!
+//! A held message is queued as any other, but released [`HOLD_SECONDS`]
+//! from now, the queue's own future-release mechanism: nothing about the
+//! queue's stored format changes, so a node on an older version reads it
+//! and simply never sends it. Beside it, a review record under `R` `h` +
+//! queue id (u64) says why it's held, for the review queue.
+//!
+//! A reviewer releases it (it's rescheduled from the queue's settings and
+//! delivered) or rejects it (it's removed, and the sender told). Unreviewed
+//! mail is rejected after [`KEEP_DAYS`].
+
+use serde::{Deserialize as SerdeDeserialize, Serialize as SerdeSerialize, de::DeserializeOwned};
+use store::{
+    Deserialize, IterateParams, SUBSPACE_INBUXA, Serialize, Store, ValueKey,
+    write::{AnyClass, BatchBuilder, ValueClass},
+};
+use trc::AddContext;
+
+const FEATURE: u8 = b'R';
+const KIND_HELD: u8 = b'h';
+
+/// 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).
+pub const KEEP_DAYS: u64 = 7;
+
+/// A rule that held the message, with its notice.
+#[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+pub struct HeldRule {
+    pub name: String,
+    pub notice: String,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, SerdeSerialize, SerdeDeserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Held {
+    pub queue_id: u64,
+    pub sender: String,
+    #[serde(default)]
+    pub account_id: Option<u32>,
+    #[serde(default)]
+    pub tenant_id: Option<u32>,
+    pub recipients: Vec<String>,
+    pub subject: String,
+    pub size: u64,
+    pub rules: Vec<HeldRule>,
+    /// Each detector that counted, and its count.
+    #[serde(default)]
+    pub counts: Vec<(String, usize)>,
+    /// Seconds since the epoch.
+    pub held_at: u64,
+    pub expires_at: u64,
+}
+
+impl Held {
+    pub fn is_expired(&self, now: u64) -> bool {
+        now >= self.expires_at
+    }
+}
+
+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 held message")
+                .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 held message")
+                .reason(err)
+        })
+    }
+}
+
+fn class(queue_id: u64) -> ValueClass {
+    let mut key = Vec::with_capacity(10);
+    key.push(FEATURE);
+    key.push(KIND_HELD);
+    key.extend_from_slice(&queue_id.to_be_bytes());
+    ValueClass::Any(AnyClass {
+        subspace: SUBSPACE_INBUXA,
+        key,
+    })
+}
+
+fn key(queue_id: u64) -> ValueKey<ValueClass> {
+    ValueKey::from(class(queue_id))
+}
+
+pub async fn get(data: &Store, queue_id: u64) -> trc::Result<Option<Held>> {
+    Ok(data
+        .get_value::<Json<Held>>(key(queue_id))
+        .await
+        .caused_by(trc::location!())?
+        .map(|Json(held)| held))
+}
+
+pub async fn is_held(data: &Store, queue_id: u64) -> trc::Result<bool> {
+    get(data, queue_id).await.map(|held| held.is_some())
+}
+
+/// Every held message, oldest first.
+pub async fn all(data: &Store) -> trc::Result<Vec<Held>> {
+    let mut held = Vec::new();
+    data.iterate(IterateParams::new(key(0), key(u64::MAX)), |_, value| {
+        if let Ok(Json(record)) = Json::<Held>::deserialize(value) {
+            held.push(record);
+        }
+        Ok(true)
+    })
+    .await
+    .caused_by(trc::location!())?;
+    held.sort_by_key(|h| (h.held_at, h.queue_id));
+    Ok(held)
+}
+
+pub async fn create(data: &Store, held: &Held) -> trc::Result<()> {
+    let mut batch = BatchBuilder::new();
+    batch.set(class(held.queue_id), Json(held).serialize()?);
+    data.write(batch.build_all())
+        .await
+        .caused_by(trc::location!())?;
+    Ok(())
+}
+
+pub async fn delete(data: &Store, queue_id: u64) -> trc::Result<()> {
+    let mut batch = BatchBuilder::new();
+    batch.clear(class(queue_id));
+    data.write(batch.build_all())
+        .await
+        .caused_by(trc::location!())?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn wire_format_and_expiry() {
+        let held = Held {
+            queue_id: 42,
+            sender: "[email protected]".into(),
+            account_id: Some(7),
+            tenant_id: None,
+            recipients: vec!["[email protected]".into()],
+            subject: "Numbers".into(),
+            size: 900,
+            rules: vec![HeldRule {
+                name: "Cards".into(),
+                notice: "Held for review".into(),
+            }],
+            counts: vec![("payment-card".into(), 5)],
+            held_at: 1_000,
+            expires_at: 1_000 + KEEP_DAYS * 86_400,
+        };
+        let json = serde_json::to_value(&held).unwrap();
+        assert_eq!(json["heldAt"], 1_000);
+        assert_eq!(serde_json::from_value::<Held>(json).unwrap(), held);
+        assert!(!held.is_expired(1_000 + KEEP_DAYS * 86_400 - 1));
+        assert!(held.is_expired(1_000 + KEEP_DAYS * 86_400));
+        assert!(HOLD_SECONDS > 90 * 365 * 86_400);
+    }
+}

crates/features/src/mailflow/mod.rs

@@ -26,6 +26,7 @@ pub mod cache;
 pub mod detectors;
 pub mod engine;
 pub mod extract;
+pub mod held;
 pub mod rewrite;
 pub mod rules;
 pub mod words;

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

@@ -0,0 +1,213 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:HeldMessage/get` and `/set` under `urn:inbuxa:jmap`: mail held
+//! for review (dlp-and-mail-flow-rules spec, §2.6). Get lists it; `preview`
+//! (the text, only when asked for) is recorded as access to someone's mail.
+//! Set only updates: `{"decision": "release"}`, or `"reject"` with an
+//! optional `note` for the sender. The call's `reason` goes into the audit
+//! log and is required.
+
+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 HeldMessage;
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum HeldMessageProperty {
+    Id,
+    Sender,
+    Recipients,
+    Subject,
+    Size,
+    Rules,
+    Counts,
+    HeldAt,
+    ExpiresAt,
+    Preview,
+    Decision,
+    Note,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum HeldMessageValue {
+    Id(Id),
+}
+
+impl Property for HeldMessageProperty {
+    fn try_parse(parent: Option<&Key<'_, Self>>, value: &str) -> Option<Self> {
+        // Keys inside rules and counts stay plain keys
+        match parent {
+            None => HeldMessageProperty::parse(value),
+            Some(_) => None,
+        }
+    }
+
+    fn to_cow(&self) -> Cow<'static, str> {
+        match self {
+            HeldMessageProperty::Id => "id",
+            HeldMessageProperty::Sender => "sender",
+            HeldMessageProperty::Recipients => "recipients",
+            HeldMessageProperty::Subject => "subject",
+            HeldMessageProperty::Size => "size",
+            HeldMessageProperty::Rules => "rules",
+            HeldMessageProperty::Counts => "counts",
+            HeldMessageProperty::HeldAt => "heldAt",
+            HeldMessageProperty::ExpiresAt => "expiresAt",
+            HeldMessageProperty::Preview => "preview",
+            HeldMessageProperty::Decision => "decision",
+            HeldMessageProperty::Note => "note",
+        }
+        .into()
+    }
+}
+
+impl HeldMessageProperty {
+    fn parse(value: &str) -> Option<Self> {
+        hashify::tiny_map!(value.as_bytes(),
+            b"id" => HeldMessageProperty::Id,
+            b"sender" => HeldMessageProperty::Sender,
+            b"recipients" => HeldMessageProperty::Recipients,
+            b"subject" => HeldMessageProperty::Subject,
+            b"size" => HeldMessageProperty::Size,
+            b"rules" => HeldMessageProperty::Rules,
+            b"counts" => HeldMessageProperty::Counts,
+            b"heldAt" => HeldMessageProperty::HeldAt,
+            b"expiresAt" => HeldMessageProperty::ExpiresAt,
+            b"preview" => HeldMessageProperty::Preview,
+            b"decision" => HeldMessageProperty::Decision,
+            b"note" => HeldMessageProperty::Note,
+        )
+    }
+}
+
+impl FromStr for HeldMessageProperty {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        HeldMessageProperty::parse(s).ok_or(())
+    }
+}
+
+impl Element for HeldMessageValue {
+    type Property = HeldMessageProperty;
+
+    fn try_parse<P>(key: &Key<'_, Self::Property>, value: &str) -> Option<Self> {
+        match key {
+            Key::Property(HeldMessageProperty::Id) => {
+                Id::from_str(value).ok().map(HeldMessageValue::Id)
+            }
+            _ => None,
+        }
+    }
+
+    fn to_cow(&self) -> Cow<'static, str> {
+        match self {
+            HeldMessageValue::Id(id) => id.to_string().into(),
+        }
+    }
+}
+
+/// The set call's own argument: why, for the audit log (required).
+#[derive(Debug, Clone, Default)]
+pub struct HeldMessageSetArguments {
+    pub reason: Option<String>,
+}
+
+impl<'de> DeserializeArguments<'de> for HeldMessageSetArguments {
+    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 HeldMessage {
+    type Property = HeldMessageProperty;
+
+    type Element = HeldMessageValue;
+
+    type Id = Id;
+
+    type Filter = ();
+
+    type Comparator = ();
+
+    type GetArguments = ();
+
+    type SetArguments<'de> = HeldMessageSetArguments;
+
+    type QueryArguments = ();
+
+    type CopyArguments = ();
+
+    type ParseArguments = ();
+
+    const ID_PROPERTY: Self::Property = HeldMessageProperty::Id;
+}
+
+impl From<Id> for HeldMessageValue {
+    fn from(id: Id) -> Self {
+        HeldMessageValue::Id(id)
+    }
+}
+
+impl JmapObjectId for HeldMessageValue {
+    fn as_id(&self) -> Option<Id> {
+        match self {
+            HeldMessageValue::Id(id) => Some(*id),
+        }
+    }
+
+    fn as_any_id(&self) -> Option<AnyId> {
+        match self {
+            HeldMessageValue::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 = HeldMessageValue::Id(id);
+            true
+        } else {
+            false
+        }
+    }
+}
+
+impl JmapObjectId for HeldMessageProperty {
+    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

@@ -29,6 +29,7 @@ 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_held_message; // inbuxa: mail held for review
 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

@@ -85,6 +85,9 @@ impl Response<'_> {
                         GetResponseMethod::MailRule(response) => {
                             response.eval_jptr(path, &mut results)
                         }
+                        GetResponseMethod::HeldMessage(response) => {
+                            response.eval_jptr(path, &mut results)
+                        }
                         GetResponseMethod::HoldExport(response) => {
                             response.eval_jptr(path, &mut results)
                         }

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

@@ -54,6 +54,7 @@ impl Response<'_> {
                 GetRequestMethod::AccountLock(request) => request.resolve_references(self)?,
                 GetRequestMethod::LegalHold(request) => request.resolve_references(self)?,
                 GetRequestMethod::MailRule(request) => request.resolve_references(self)?,
+                GetRequestMethod::HeldMessage(request) => request.resolve_references(self)?,
                 GetRequestMethod::HoldExport(request) => request.resolve_references(self)?,
                 GetRequestMethod::ProtocolPolicy(request) => request.resolve_references(self)?,
                 GetRequestMethod::TenantProtocolPolicy(request) => {
@@ -126,6 +127,9 @@ impl Response<'_> {
                 SetRequestMethod::MailRule(request) => {
                     request.resolve_references(self, 1, false)?
                 }
+                SetRequestMethod::HeldMessage(request) => {
+                    request.resolve_references(self, 1, false)?
+                }
                 SetRequestMethod::HoldExport(request) => {
                     request.resolve_references(self, 1, false)?
                 }

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

@@ -67,6 +67,7 @@ pub enum MethodObject {
     ProtocolPolicy,
     // inbuxa: DLP and mail flow rules
     MailRule,
+    HeldMessage,
     TenantProtocolPolicy,
 }
 
@@ -105,7 +106,8 @@ impl MethodObject {
             | MethodObject::AccountLock
             | MethodObject::LegalHold
             | MethodObject::HoldExport
-            | MethodObject::MailRule => Capability::Inbuxa,
+            | MethodObject::MailRule
+            | MethodObject::HeldMessage => Capability::Inbuxa,
             MethodObject::ProtocolPolicy => Capability::Inbuxa,
             MethodObject::TenantProtocolPolicy => Capability::Inbuxa,
         }
@@ -301,6 +303,8 @@ impl MethodName {
             (MethodFunction::Set, MethodObject::LegalHold) => "inbuxa:LegalHold/set",
             (MethodFunction::Get, MethodObject::MailRule) => "inbuxa:MailRule/get",
             (MethodFunction::Set, MethodObject::MailRule) => "inbuxa:MailRule/set",
+            (MethodFunction::Get, MethodObject::HeldMessage) => "inbuxa:HeldMessage/get",
+            (MethodFunction::Set, MethodObject::HeldMessage) => "inbuxa:HeldMessage/set",
             (MethodFunction::Get, MethodObject::HoldExport) => "inbuxa:HoldExport/get",
             (MethodFunction::Set, MethodObject::HoldExport) => "inbuxa:HoldExport/set",
             (MethodFunction::Set, MethodObject::AuditVerification) => {
@@ -455,6 +459,8 @@ impl MethodName {
             "inbuxa:LegalHold/set" => (MethodObject::LegalHold, MethodFunction::Set),
             "inbuxa:MailRule/get" => (MethodObject::MailRule, MethodFunction::Get),
             "inbuxa:MailRule/set" => (MethodObject::MailRule, MethodFunction::Set),
+            "inbuxa:HeldMessage/get" => (MethodObject::HeldMessage, MethodFunction::Get),
+            "inbuxa:HeldMessage/set" => (MethodObject::HeldMessage, MethodFunction::Set),
             "inbuxa:HoldExport/get" => (MethodObject::HoldExport, MethodFunction::Get),
             "inbuxa:HoldExport/set" => (MethodObject::HoldExport, MethodFunction::Set),
             "inbuxa:AuditVerification/set" => (MethodObject::AuditVerification, MethodFunction::Set),
@@ -526,6 +532,7 @@ impl Display for MethodObject {
             MethodObject::AccountLock => "inbuxa:AccountLock",
             MethodObject::LegalHold => "inbuxa:LegalHold",
             MethodObject::MailRule => "inbuxa:MailRule",
+            MethodObject::HeldMessage => "inbuxa:HeldMessage",
             MethodObject::HoldExport => "inbuxa:HoldExport",
             MethodObject::ProtocolPolicy => "inbuxa:ProtocolPolicy",
             MethodObject::TenantProtocolPolicy => "inbuxa:TenantProtocolPolicy",

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

@@ -124,6 +124,7 @@ pub enum GetRequestMethod {
     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>>),
+    HeldMessage(Box<GetRequest<crate::object::inbuxa_held_message::HeldMessage>>),
     HoldExport(Box<GetRequest<crate::object::inbuxa_hold_export::HoldExport>>),
     ProtocolPolicy(Box<GetRequest<crate::object::inbuxa_protocol_policy::ProtocolPolicy>>),
     TenantProtocolPolicy(
@@ -160,6 +161,7 @@ pub enum SetRequestMethod<'x> {
     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>>),
+    HeldMessage(Box<SetRequest<'x, crate::object::inbuxa_held_message::HeldMessage>>),
     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: mail held for review
+            (MethodFunction::Get, MethodObject::HeldMessage) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::HeldMessage(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
+            (MethodFunction::Set, MethodObject::HeldMessage) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Set(SetRequestMethod::HeldMessage(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    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)),

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

@@ -111,6 +111,7 @@ pub enum GetResponseMethod {
     AccountLock(GetResponse<crate::object::inbuxa_account_lock::AccountLock>),
     LegalHold(GetResponse<crate::object::inbuxa_legal_hold::LegalHold>),
     MailRule(GetResponse<crate::object::inbuxa_mail_rule::MailRule>),
+    HeldMessage(GetResponse<crate::object::inbuxa_held_message::HeldMessage>),
     HoldExport(GetResponse<crate::object::inbuxa_hold_export::HoldExport>),
     ProtocolPolicy(GetResponse<crate::object::inbuxa_protocol_policy::ProtocolPolicy>),
     TenantProtocolPolicy(
@@ -147,6 +148,7 @@ pub enum SetResponseMethod {
     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>>),
+    HeldMessage(Box<SetResponse<crate::object::inbuxa_held_message::HeldMessage>>),
     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>>),
@@ -801,6 +803,18 @@ impl<'x> From<SetResponse<crate::object::inbuxa_account_lock::AccountLock>> for
 }
 
 // inbuxa: legal hold
+impl<'x> From<GetResponse<crate::object::inbuxa_held_message::HeldMessage>> for ResponseMethod<'x> {
+    fn from(value: GetResponse<crate::object::inbuxa_held_message::HeldMessage>) -> Self {
+        ResponseMethod::Get(GetResponseMethod::HeldMessage(value))
+    }
+}
+
+impl<'x> From<SetResponse<crate::object::inbuxa_held_message::HeldMessage>> for ResponseMethod<'x> {
+    fn from(value: SetResponse<crate::object::inbuxa_held_message::HeldMessage>) -> Self {
+        ResponseMethod::Set(SetResponseMethod::HeldMessage(Box::new(value)))
+    }
+}
+
 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))

crates/jmap/src/api/auth.rs

@@ -106,6 +106,8 @@ impl JmapAuthorization for AccessToken {
                 // 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
+                // inbuxa: mail held for review (§2.8)
+                GetRequestMethod::HeldMessage(_) => Permission::SysDlpReviewGet,
                 GetRequestMethod::MailRule(_) => {
                     if self.has_permission(Permission::SysMailRuleGet) {
                         Permission::SysMailRuleGet
@@ -257,6 +259,14 @@ impl JmapAuthorization for AccessToken {
                         Permission::SysLegalHoldUpdate,
                         Permission::SysLegalHoldUpdate,
                     ),
+                    // inbuxa: releasing or rejecting held mail (§2.8)
+                    SetRequestMethod::HeldMessage(s) => validate_set(
+                        s,
+                        self,
+                        Permission::SysDlpReviewUpdate,
+                        Permission::SysDlpReviewUpdate,
+                        Permission::SysDlpReviewUpdate,
+                    ),
                     // inbuxa: DLP and mail flow rules: either change
                     // permission gets in; the handler checks each rule's kind
                     SetRequestMethod::MailRule(_) => {
@@ -431,6 +441,7 @@ impl JmapAuthorization for AccessToken {
                 | MethodObject::LegalHold
                 | MethodObject::HoldExport
                 | MethodObject::MailRule
+                | MethodObject::HeldMessage
                 | MethodObject::ProtocolPolicy
                 | MethodObject::TenantProtocolPolicy => Permission::JmapEmailChanges,
                 // inbuxa: x:MaskedEmail/changes reads what /get reads

crates/jmap/src/api/request.rs

@@ -282,6 +282,9 @@ impl RequestHandler for Server {
                                     SetResponseMethod::MailRule(set_response) => {
                                         set_response.update_created_ids(&mut response);
                                     }
+                                    SetResponseMethod::HeldMessage(set_response) => {
+                                        set_response.update_created_ids(&mut response);
+                                    }
                                     SetResponseMethod::HoldExport(set_response) => {
                                         set_response.update_created_ids(&mut response);
                                     }
@@ -489,6 +492,11 @@ 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: mail held for review
+                GetRequestMethod::HeldMessage(mut req) => {
+                    resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
+                    crate::inbuxa::held_message::get(self, access_token, *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)?;
@@ -918,6 +926,22 @@ impl RequestHandler for Server {
                     .await?
                     .into()
                 }
+                SetRequestMethod::HeldMessage(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::held_message::set(self, access_token, req)),
+                    )
+                    .await?
+                    .into()
+                }
                 SetRequestMethod::MailRule(mut req) => {
                     resolve_account_id(&mut req.account_id, method_name.obj, access_token)?;
                     let reason = req.arguments.reason.clone();

crates/jmap/src/changes/get.rs

@@ -430,6 +430,7 @@ impl IntermediateChangesResponse {
             | MethodObject::LegalHold
             | MethodObject::HoldExport
             | MethodObject::MailRule
+            | MethodObject::HeldMessage
             | MethodObject::ProtocolPolicy
             | MethodObject::TenantProtocolPolicy
             | MethodObject::Registry(_) => unreachable!(),

crates/jmap/src/inbuxa/held_message.rs

@@ -0,0 +1,325 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! `inbuxa:HeldMessage` (dlp-and-mail-flow-rules spec, §2.6, §2.8): the
+//! review queue. `sysDlpReviewGet` lists held mail and reads it;
+//! `sysDlpReviewUpdate` releases or rejects it, with a reason the request
+//! layer records. Reading a held message's text is recorded as access to
+//! the sender's mail. Nobody in a tenant reaches this (settled answer 3).
+
+use common::{Server, auth::AccessToken, config::smtp::queue::QueueName};
+use inbuxa_features::{
+    audit::{Action, Outcome, Record, Target},
+    mailflow::held::{self, Held},
+};
+use jmap_proto::{
+    error::set::SetError,
+    method::{
+        get::{GetRequest, GetResponse},
+        set::{SetRequest, SetResponse},
+    },
+    object::inbuxa_held_message::{
+        HeldMessage, HeldMessageProperty as P, HeldMessageSetArguments, HeldMessageValue,
+    },
+    request::IntoValid,
+    types::date::UTCDate,
+};
+use jmap_tools::{Key, Map, Value};
+use mail_parser::{MessageParser, MimeHeaders, PartType};
+use smtp::queue::spool::SmtpSpool;
+use std::borrow::Cow;
+use types::id::Id;
+
+type HValue = Value<'static, P, HeldMessageValue>;
+
+const ALL: &[P] = &[
+    P::Id,
+    P::Sender,
+    P::Recipients,
+    P::Subject,
+    P::Size,
+    P::Rules,
+    P::Counts,
+    P::HeldAt,
+    P::ExpiresAt,
+];
+
+/// How much of a held message's text a preview shows.
+const PREVIEW_LIMIT: usize = 64 * 1024;
+
+fn server_level(access_token: &AccessToken) -> trc::Result<()> {
+    if access_token.tenant_id().is_some() {
+        Err(trc::JmapEvent::Forbidden
+            .into_err()
+            .details("Held mail is the server's to review."))
+    } else {
+        Ok(())
+    }
+}
+
+fn date(seconds: u64) -> HValue {
+    Value::Str(UTCDate::from_timestamp(seconds as i64).to_string().into())
+}
+
+fn text(s: &str) -> HValue {
+    Value::Str(Cow::Owned(s.to_string()))
+}
+
+/// The text a reviewer reads: the subject, each body as text, and the
+/// attachments' names; at most [`PREVIEW_LIMIT`].
+async fn preview(server: &Server, queue_id: u64) -> trc::Result<Option<String>> {
+    let Some(message) = server.read_message(queue_id, QueueName::default()).await else {
+        return Ok(None);
+    };
+    let Some(raw) = server
+        .blob_store()
+        .get_blob(message.message.blob_hash.as_slice(), 0..usize::MAX)
+        .await?
+    else {
+        return Ok(None);
+    };
+    let Some(parsed) = MessageParser::new().parse(&raw) else {
+        return Ok(Some(
+            String::from_utf8_lossy(&raw[..raw.len().min(PREVIEW_LIMIT)]).into_owned(),
+        ));
+    };
+    let mut out = String::new();
+    for part in parsed.text_bodies() {
+        match &part.body {
+            PartType::Text(text) => out.push_str(text),
+            PartType::Html(html) => out.push_str(&mail_parser::decoders::html::html_to_text(html)),
+            _ => {}
+        }
+        out.push_str("\n\n");
+    }
+    let attachments: Vec<&str> = parsed
+        .attachments()
+        .filter_map(|a| a.attachment_name())
+        .collect();
+    if !attachments.is_empty() {
+        out.push_str(&format!("Attachments: {}\n", attachments.join(", ")));
+    }
+    if out.len() > PREVIEW_LIMIT {
+        let mut cut = PREVIEW_LIMIT;
+        while !out.is_char_boundary(cut) {
+            cut -= 1;
+        }
+        out.truncate(cut);
+    }
+    Ok(Some(out))
+}
+
+fn to_value(record: &Held, properties: &[P], preview: Option<&str>) -> HValue {
+    let mut out = Map::with_capacity(properties.len());
+    for property in properties {
+        let value = match property {
+            P::Id => Value::Element(HeldMessageValue::Id(Id::from(record.queue_id))),
+            P::Sender => text(&record.sender),
+            P::Recipients => Value::Array(record.recipients.iter().map(|r| text(r)).collect()),
+            P::Subject => text(&record.subject),
+            P::Size => Value::Number(record.size.into()),
+            P::Rules => Value::Array(
+                record
+                    .rules
+                    .iter()
+                    .map(|rule| {
+                        let mut map = Map::with_capacity(2);
+                        map.insert_unchecked(Key::Borrowed("name"), text(&rule.name));
+                        map.insert_unchecked(Key::Borrowed("notice"), text(&rule.notice));
+                        Value::Object(map)
+                    })
+                    .collect(),
+            ),
+            P::Counts => Value::Array(
+                record
+                    .counts
+                    .iter()
+                    .map(|(detector, count)| {
+                        let mut map = Map::with_capacity(2);
+                        map.insert_unchecked(Key::Borrowed("detector"), text(detector));
+                        map.insert_unchecked(
+                            Key::Borrowed("count"),
+                            Value::Number((*count as u64).into()),
+                        );
+                        Value::Object(map)
+                    })
+                    .collect(),
+            ),
+            P::HeldAt => date(record.held_at),
+            P::ExpiresAt => date(record.expires_at),
+            P::Preview => preview.map_or(Value::Null, text),
+            P::Decision | P::Note => Value::Null,
+        };
+        out.insert_unchecked(Key::Property(property.clone()), value);
+    }
+    Value::Object(out)
+}
+
+/// `inbuxa:HeldMessage/get`: held mail, oldest first.
+pub async fn get(
+    server: &Server,
+    access_token: &AccessToken,
+    mut request: GetRequest<HeldMessage>,
+) -> trc::Result<GetResponse<HeldMessage>> {
+    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 all = held::all(server.store()).await?;
+    let wanted: Vec<&Held> = match &ids {
+        None => all.iter().collect(),
+        Some(ids) => {
+            let mut found = Vec::new();
+            for id in ids {
+                match all.iter().find(|h| h.queue_id == id.id()) {
+                    Some(record) => found.push(record),
+                    None => response.push_not_found(*id),
+                }
+            }
+            found
+        }
+    };
+    let with_preview = properties.contains(&P::Preview);
+    for record in wanted {
+        let text = if with_preview {
+            let text = preview(server, record.queue_id).await?;
+            // Reading someone's mail is recorded, as any access is
+            server
+                .audit_note(Record {
+                    at: store::write::now() * 1000,
+                    actor: server.audit_actor(access_token).await,
+                    via: access_token.origin().cloned(),
+                    remote_ip: None,
+                    action: Action::BlobAccess,
+                    target: Target {
+                        kind: "inbuxa:HeldMessage".into(),
+                        id: Some(Id::from(record.queue_id).to_string()),
+                        name: Some(record.subject.clone()),
+                        account_id: record.account_id,
+                        tenant_id: record.tenant_id,
+                    },
+                    changes: vec![],
+                    details: Some(format!(
+                        "Read a message held for review, from {}",
+                        record.sender
+                    )),
+                    reason: None,
+                    outcome: Outcome::success(),
+                })
+                .await;
+            text
+        } else {
+            None
+        };
+        response
+            .list
+            .push(to_value(record, &properties, text.as_deref()));
+    }
+    Ok(response)
+}
+
+fn invalid(property: P, why: &str) -> SetError<P> {
+    SetError::invalid_properties()
+        .with_property(property)
+        .with_description(why.to_string())
+}
+
+/// `inbuxa:HeldMessage/set`: update with `decision` release or reject (and
+/// an optional `note` for the sender). There is no create or destroy.
+pub async fn set(
+    server: &Server,
+    access_token: &AccessToken,
+    mut request: SetRequest<'_, HeldMessage>,
+) -> trc::Result<SetResponse<HeldMessage>> {
+    server_level(access_token)?;
+    let mut response = SetResponse::from_request(&request, server.core.jmap.set_max_objects)?;
+    let arguments: HeldMessageSetArguments = std::mem::take(&mut request.arguments);
+    let has_reason = arguments
+        .reason
+        .as_deref()
+        .is_some_and(|r| !r.trim().is_empty());
+
+    for (client_id, _) in request.unwrap_create() {
+        response.not_created.append(
+            client_id,
+            SetError::forbidden().with_description("Mail is held by DLP rules, not created."),
+        );
+    }
+
+    'update: for (id, value) in request.unwrap_update().into_valid() {
+        let Some(record) = held::get(server.store(), id.id()).await? else {
+            response.not_updated.append(id, SetError::not_found());
+            continue;
+        };
+        if !has_reason {
+            response.not_updated.append(
+                id,
+                SetError::invalid_properties().with_description(
+                    "Say why: a reason is required and is kept in the audit log.",
+                ),
+            );
+            continue;
+        }
+        let mut decision = None;
+        let mut note = None;
+        for (key, value) in value.into_expanded_object() {
+            match (&key, value) {
+                (Key::Property(P::Decision), Value::Str(s)) if s == "release" || s == "reject" => {
+                    decision = Some(s.to_string());
+                }
+                (Key::Property(P::Note), Value::Str(s)) => {
+                    let s = s.trim();
+                    if !s.is_empty() {
+                        note = Some(s.chars().take(1000).collect::<String>());
+                    }
+                }
+                (Key::Property(P::Note), Value::Null) => {}
+                _ => {
+                    response.not_updated.append(
+                        id,
+                        invalid(
+                            P::Decision,
+                            "Send decision: \"release\" or \"reject\", and an optional note.",
+                        ),
+                    );
+                    continue 'update;
+                }
+            }
+        }
+        let done = match decision.as_deref() {
+            Some("release") => smtp::queue::held::release(server, record.queue_id).await?,
+            Some("reject") => smtp::queue::held::reject(server, &record, note.as_deref()).await?,
+            _ => {
+                response
+                    .not_updated
+                    .append(id, invalid(P::Decision, "Say release or reject."));
+                continue;
+            }
+        };
+        if done {
+            response.updated.append(id, None);
+        } else {
+            response.not_updated.append(
+                id,
+                SetError::not_found().with_description("The message is no longer in the queue."),
+            );
+        }
+    }
+
+    for id in request.unwrap_destroy().into_valid() {
+        response.not_destroyed.append(
+            id,
+            SetError::forbidden().with_description("Release or reject it instead."),
+        );
+    }
+
+    Ok(response)
+}

crates/jmap/src/inbuxa/mod.rs

@@ -11,6 +11,7 @@ pub mod access;
 pub mod account_lock;
 pub mod legal_hold;
 pub mod mail_rule;
+pub mod held_message;
 pub mod hold_export;
 pub mod hold_export_api;
 pub mod audit;

crates/jmap/src/registry/mapping/queued_message.rs

@@ -49,6 +49,12 @@ use trc::AddContext;
 use types::{blob::BlobId, blob_hash::BlobHash, id::Id};
 use utils::map::vec_map::VecMap;
 
+/// inbuxa: held mail is the review queue's to decide.
+fn held_refusal() -> SetError<Property> {
+    SetError::forbidden()
+        .with_description("This message is held for review: release or reject it under Compliance, Held mail.")
+}
+
 pub(crate) async fn queued_message_set(
     mut set: RegistrySetResponse<'_>,
 ) -> trc::Result<RegistrySetResponse<'_>> {
@@ -66,6 +72,12 @@ pub(crate) async fn queued_message_set(
     let mut refresh_queue = false;
     'outer: for (id, value) in set.update.drain(..) {
         let queue_id = id.id();
+        // inbuxa: held mail is released or rejected by review, not here
+        // (dlp-and-mail-flow-rules spec, §2.6)
+        if inbuxa_features::mailflow::held::is_held(set.server.store(), queue_id).await? {
+            set.response.not_updated.append(id, held_refusal());
+            continue;
+        }
         let Some(archive) = set.server.read_message_archive(queue_id).await? else {
             set.response.not_updated.append(id, SetError::not_found());
             continue;
@@ -238,6 +250,11 @@ pub(crate) async fn queued_message_set(
 
     // Process destroy operations
     for id in set.destroy.drain(..) {
+        // inbuxa: §2.6, as above
+        if inbuxa_features::mailflow::held::is_held(set.server.store(), id.id()).await? {
+            set.response.not_destroyed.append(id, held_refusal());
+            continue;
+        }
         let Some(message) = set.server.read_message(id.id(), QueueName::default()).await else {
             set.response.not_destroyed.append(id, SetError::not_found());
             continue;

crates/jmap/src/submission/set.rs

@@ -214,6 +214,17 @@ impl EmailSubmissionSet for Server {
             }
 
             match undo_status {
+                // inbuxa: held for review: the review decides, not an unsend
+                // (dlp-and-mail-flow-rules spec, §2.6)
+                Some(email_submission::UndoStatus::Canceled)
+                    if inbuxa_features::mailflow::held::is_held(self.store(), queue_id).await? =>
+                {
+                    response.not_updated.append(
+                        id,
+                        SetError::new(SetErrorType::CannotUnsend)
+                            .with_description("The message is held for review and can't be unsent."),
+                    );
+                }
                 Some(email_submission::UndoStatus::Canceled) => {
                     if let Some(queue_message) =
                         self.read_message(queue_id, QueueName::default()).await

crates/services/src/task_manager/maintenance.rs

@@ -286,6 +286,11 @@ async fn store_maintenance(
                 trc::error!(err.details("Failed to purge expired IP bans"));
             }
 
+            // inbuxa: DLP, §2.6: mail nobody reviewed in time goes back
+            if let Err(err) = smtp::queue::held::expire(server).await {
+                trc::error!(err.details("Failed to return unreviewed held mail"));
+            }
+
             // inbuxa: AU-7: audit records past their retention go; a
             // failure leaves them for the next run
             if let Err(err) = server.audit_purge().await {

crates/smtp/src/inbound/data.rs

@@ -740,35 +740,46 @@ impl<T: SessionStream> Session<T> {
 
         // inbuxa: DLP (dlp-and-mail-flow-rules spec, §2.1): after the system
         // script, before headers and signing
-        match self
+        let mut held_draft = None;
+        let (message, envelope) = match self
             .check_mail_rules(edited_message.as_deref().unwrap_or(raw_message.as_slice()))
             .await
         {
-            super::mailflow::Checked::Accept => {}
+            super::mailflow::Checked::Accept => (None, Vec::new()),
-            super::mailflow::Checked::Changed { message, envelope } => {
+            super::mailflow::Checked::Changed { message, envelope } => (message, envelope),
-                if let Some(message) = message {
+            // §2.6: queued, but not due for a century; a reviewer releases it
-                    edited_message = Some(message);
+            super::mailflow::Checked::Hold { draft, message, envelope } => {
-                }
+                self.data.future_release = inbuxa_features::mailflow::held::HOLD_SECONDS;
-                for change in envelope {
+                held_draft = Some(draft);
-                    match change {
+                (message, envelope)
-                        super::mailflow::EnvelopeChange::AddRecipient(address) => {
-                            if !self.data.rcpt_to.iter().any(|r| r.address_lcase.eq_ignore_ascii_case(&address)) {
-                                self.data.rcpt_to.push(SessionAddress::new(address));
-                            }
-                        }
-                        super::mailflow::EnvelopeChange::Redirect(addresses) => {
-                            self.data.rcpt_to = addresses.into_iter().map(SessionAddress::new).collect();
-                        }
-                        super::mailflow::EnvelopeChange::Route(queue) => {
-                            self.data.mailflow_queue = Some(queue);
-                        }
-                    }
-                }
             }
             super::mailflow::Checked::Refuse(reply, refusal) => {
                 self.data.dlp_refusal = refusal;
                 return reply.into();
             }
+        };
+        if let Some(message) = message {
+            edited_message = Some(message);
+        }
+        for change in envelope {
+            match change {
+                super::mailflow::EnvelopeChange::AddRecipient(address) => {
+                    if !self
+                        .data
+                        .rcpt_to
+                        .iter()
+                        .any(|r| r.address_lcase.eq_ignore_ascii_case(&address))
+                    {
+                        self.data.rcpt_to.push(SessionAddress::new(address));
+                    }
+                }
+                super::mailflow::EnvelopeChange::Redirect(addresses) => {
+                    self.data.rcpt_to = addresses.into_iter().map(SessionAddress::new).collect();
+                }
+                super::mailflow::EnvelopeChange::Route(queue) => {
+                    self.data.mailflow_queue = Some(queue);
+                }
+            }
         }
 
         // Build message
@@ -850,6 +861,19 @@ impl<T: SessionStream> Session<T> {
                 .server
                 .eval_signers(&ac.dkim.sign, self, self.data.session_id)
                 .await;
+            // inbuxa: §2.6, who the held message is from and to
+            let held_envelope = held_draft.as_ref().map(|_| {
+                (
+                    message.message.return_path.to_string(),
+                    message
+                        .message
+                        .recipients
+                        .iter()
+                        .map(|r| r.address.to_string())
+                        .collect::<Vec<_>>(),
+                    message.message.size,
+                )
+            });
             if message
                 .queue(
                     QueueParams::new(raw_message, self.data.session_id, &self.server)
@@ -864,9 +888,17 @@ impl<T: SessionStream> Session<T> {
             {
                 self.state = State::Accepted(queue_id);
                 self.data.messages_sent += 1;
-                format!("250 2.0.0 Message queued with id {queue_id:x}.\r\n")
+                if let (Some(draft), Some((sender, recipients, size))) = (held_draft, held_envelope)
-                    .into_bytes()
+                {
-                    .into()
+                    self.record_held(queue_id, draft, sender, recipients, size).await;
+                    format!("250 2.0.0 Held for review, id {queue_id:x}.\r\n")
+                        .into_bytes()
+                        .into()
+                } else {
+                    format!("250 2.0.0 Message queued with id {queue_id:x}.\r\n")
+                        .into_bytes()
+                        .into()
+                }
             } else {
                 (b"451 4.3.5 Unable to accept message at this time.\r\n"[..]).into()
             }

crates/smtp/src/inbound/mailflow.rs

@@ -21,6 +21,7 @@ use inbuxa_features::{
             Attachment, Content, Decision, Envelope, Outcome as RulesOutcome, Recipient, RuleRef,
         },
         extract::{self, Extracted, Limits},
+        held::{self, Held, HeldRule, KEEP_DAYS},
         rewrite,
         rules::{Action as RuleAction, Kind},
     },
@@ -44,6 +45,20 @@ pub enum Checked {
     },
     /// Refuse, with this SMTP reply, and for a JMAP submission, why.
     Refuse(Vec<u8>, Option<DlpRefusal>),
+    /// Queue it held for review (§2.6), with any transport changes.
+    Hold {
+        draft: HeldDraft,
+        message: Option<Vec<u8>>,
+        envelope: Vec<EnvelopeChange>,
+    },
+}
+
+/// What the review record will say, once the message has a queue id.
+pub struct HeldDraft {
+    pub subject: String,
+    pub rules: Vec<HeldRule>,
+    pub counts: Vec<(String, usize)>,
+    pub notify_sender: bool,
 }
 
 /// What a transport rule changes about where a message goes.
@@ -219,6 +234,7 @@ impl<T: SessionStream> Session<T> {
             None
         };
         let checked_subject = tag.as_ref().map_or(subject, |(_, rest)| rest.as_str());
+        let held_subject = checked_subject.to_string();
 
         let mut content = Content {
             subject: checked_subject,
@@ -319,22 +335,51 @@ impl<T: SessionStream> Session<T> {
             .await;
         }
 
-        match decision {
+        let hold = match decision {
-            Decision::Block(rules) | Decision::Hold { rules, .. } => {
+            Decision::Block(rules) => {
-                // Hold for review is phase 3: until then a hold rule blocks,
-                // rather than let the message through unreviewed
                 let refusal = refusal(true, &rules);
-                Checked::Refuse(format!("550 5.7.1 {}\r\n", notices(&rules)).into_bytes(), Some(refusal))
+                return Checked::Refuse(
+                    format!("550 5.7.1 {}\r\n", notices(&rules)).into_bytes(),
+                    Some(refusal),
+                );
             }
-            Decision::Warn(rules) => Checked::Refuse(
+            Decision::Warn(rules) => {
-                format!(
+                return Checked::Refuse(
-                    "550 5.7.1 {} To send anyway, start the subject with [override: your reason]\r\n",
+                    format!(
-                    notices(&rules)
+                        "550 5.7.1 {} To send anyway, start the subject with [override: your reason]\r\n",
-                )
+                        notices(&rules)
-                .into_bytes(),
+                    )
-                Some(refusal(false, &rules)),
+                    .into_bytes(),
-            ),
+                    Some(refusal(false, &rules)),
-            Decision::Pass => {
+                );
+            }
+            // Accepted and queued, but not sent until a reviewer says so
+            // (§2.6); the transport rules still apply, so what's released
+            // is what would have gone out
+            Decision::Hold {
+                rules,
+                notify_sender,
+            } => Some(HeldDraft {
+                subject: held_subject,
+                rules: rules
+                    .iter()
+                    .map(|r| HeldRule {
+                        name: r.name.clone(),
+                        notice: r.notice.clone(),
+                    })
+                    .collect(),
+                counts: outcome
+                    .matched
+                    .iter()
+                    .filter(|m| m.kind == Kind::Dlp)
+                    .flat_map(|m| m.counts.iter().cloned())
+                    .collect(),
+                notify_sender,
+            }),
+            Decision::Pass => None,
+        };
+        {
+            {
                 // The tag was an instruction to the server, not part of the
                 // subject: it doesn't go out
                 let mut current: Option<Vec<u8>> =
@@ -344,12 +389,18 @@ impl<T: SessionStream> Session<T> {
                     for action in &matched.actions {
                         let now = current.as_deref().unwrap_or(message);
                         let next = match action {
-                            RuleAction::AddDisclaimer { text, html, position } => {
+                            RuleAction::AddDisclaimer {
-                                rewrite::add_disclaimer(now, text, html.as_deref(), *position)
+                                text,
+                                html,
+                                position,
+                            } => rewrite::add_disclaimer(now, text, html.as_deref(), *position),
+                            RuleAction::AddHeader { name, value } => {
+                                Some(rewrite::add_header(now, name, value))
                             }
-                            RuleAction::AddHeader { name, value } => Some(rewrite::add_header(now, name, value)),
                             RuleAction::RemoveHeader { name } => rewrite::remove_header(now, name),
-                            RuleAction::PrefixSubject { text } => rewrite::prefix_subject(now, text),
+                            RuleAction::PrefixSubject { text } => {
+                                rewrite::prefix_subject(now, text)
+                            }
                             RuleAction::AddRecipient { address } => {
                                 changes.push(EnvelopeChange::AddRecipient(address.clone()));
                                 None
@@ -363,13 +414,16 @@ impl<T: SessionStream> Session<T> {
                                 None
                             }
                             RuleAction::Refuse { text } => {
-                                self.record_transport(&sender, &matched.name, "refused", &domains).await;
+                                self.record_transport(&sender, &matched.name, "refused", &domains)
+                                    .await;
                                 return Checked::Refuse(
                                     format!("550 5.7.1 {}\r\n", reply_text(text)).into_bytes(),
                                     None,
                                 );
                             }
-                            RuleAction::Block { .. } | RuleAction::Warn { .. } | RuleAction::Hold { .. } => None,
+                            RuleAction::Block { .. }
+                            | RuleAction::Warn { .. }
+                            | RuleAction::Hold { .. } => None,
                         };
                         if next.is_some() {
                             current = next;
@@ -381,25 +435,76 @@ impl<T: SessionStream> Session<T> {
                         .actions
                         .iter()
                         .filter_map(|a| match a {
-                            RuleAction::AddRecipient { address } => Some(format!("copied to {address}")),
+                            RuleAction::AddRecipient { address } => {
-                            RuleAction::Redirect { addresses } => Some(format!("redirected to {}", addresses.join(", "))),
+                                Some(format!("copied to {address}"))
+                            }
+                            RuleAction::Redirect { addresses } => {
+                                Some(format!("redirected to {}", addresses.join(", ")))
+                            }
                             RuleAction::Route { queue } => Some(format!("routed through {queue}")),
                             _ => None,
                         })
                         .collect();
                     if !routed.is_empty() {
-                        self.record_transport(&sender, &matched.name, &routed.join(", "), &domains).await;
+                        self.record_transport(&sender, &matched.name, &routed.join(", "), &domains)
+                            .await;
                     }
                 }
-                if current.is_none() && changes.is_empty() {
+                match hold {
-                    Checked::Accept
+                    Some(draft) => Checked::Hold {
-                } else {
+                        draft,
-                    Checked::Changed { message: current, envelope: changes }
+                        message: current,
+                        envelope: changes,
+                    },
+                    None if current.is_none() && changes.is_empty() => Checked::Accept,
+                    None => Checked::Changed {
+                        message: current,
+                        envelope: changes,
+                    },
                 }
             }
         }
     }
 
+    /// Writes the review record for a message just queued held (§2.6),
+    /// and tells the sender when the rule asks. A failure to write it is
+    /// logged: the message stays held, never sent unreviewed.
+    pub async fn record_held(
+        &self,
+        queue_id: u64,
+        draft: HeldDraft,
+        sender: String,
+        recipients: Vec<String>,
+        size: u64,
+    ) {
+        let at = store::write::now();
+        let account = self.data.authenticated_as.as_ref();
+        let record = Held {
+            queue_id,
+            sender,
+            account_id: account.map(|a| a.account_id),
+            tenant_id: account.and_then(|a| a.account.id_tenant),
+            recipients,
+            subject: draft.subject,
+            size,
+            rules: draft.rules,
+            counts: draft.counts,
+            held_at: at,
+            expires_at: at + KEEP_DAYS * 86_400,
+        };
+        if let Err(err) = held::create(self.server.store(), &record).await {
+            trc::error!(
+                err.span_id(self.data.session_id)
+                    .caused_by(trc::location!())
+                    .details("Failed to write the review record of a held message")
+            );
+            return;
+        }
+        if draft.notify_sender {
+            crate::queue::held::notify_held(&self.server, &record).await;
+        }
+    }
+
     /// A transport rule that refused a message or changed where it goes
     /// (§2.7): who sent it (or the server, for incoming mail), the rule,
     /// what it did.
@@ -485,9 +590,8 @@ impl<T: SessionStream> Session<T> {
             .collect::<Vec<_>>()
             .join("; ");
         let (what, outcome, reason) = match decision {
-            Decision::Block(_) | Decision::Hold { .. } => {
+            Decision::Hold { .. } => ("held for review", Outcome::success(), None),
-                ("blocked", Outcome::refused("inbuxa:dlpBlocked", None), None)
+            Decision::Block(_) => ("blocked", Outcome::refused("inbuxa:dlpBlocked", None), None),
-            }
             Decision::Warn(_) => ("warned", Outcome::refused("inbuxa:dlpWarning", None), None),
             Decision::Pass => (
                 "sent after a warning",

crates/smtp/src/queue/held.rs

@@ -0,0 +1,177 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Coffey Labs
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+//! inbuxa: mail held for review (dlp-and-mail-flow-rules spec, §2.6):
+//! releasing it, rejecting it, rejecting what nobody reviewed in time, and
+//! the notices the sender gets.
+//!
+//! A held message sits in the queue with its release [`HOLD_SECONDS`] off.
+//! Releasing it undoes exactly that: each recipient due now, its next
+//! notice as far from now as it was from its retry, its lifetime counted
+//! from the release.
+
+use crate::{
+    queue::{Message, MessageWrapper, Status, spool::SmtpSpool},
+    reporting::send::MtaReportSend,
+};
+use common::{
+    Server,
+    config::smtp::queue::{QueueExpiry, QueueName},
+    ipc::QueueEvent,
+};
+use inbuxa_features::{
+    audit::{Action, Actor, Outcome, Record, Target},
+    mailflow::held::{self, HOLD_SECONDS, Held, KEEP_DAYS},
+};
+use mail_builder::{
+    MessageBuilder,
+    headers::{HeaderType, address::Address},
+};
+use store::{ahash::AHashSet, write::now};
+
+/// Puts a held message back on its way. False when it's no longer queued.
+pub async fn release(server: &Server, queue_id: u64) -> trc::Result<bool> {
+    let Some(archive) = server.read_message_archive(queue_id).await? else {
+        held::delete(server.store(), queue_id).await?;
+        return Ok(false);
+    };
+    let mut message: Message = archive.to_unarchived::<Message>()?.deserialize()?;
+    let prev_events = message.next_events();
+    let at = now();
+    let mut modified = AHashSet::new();
+    for (idx, rcpt) in message.recipients.iter_mut().enumerate() {
+        if !matches!(rcpt.status, Status::Scheduled | Status::TemporaryFailure(_)) {
+            continue;
+        }
+        let notify_gap = rcpt.notify.due.saturating_sub(rcpt.retry.due);
+        rcpt.retry.due = at;
+        rcpt.notify.due = at + notify_gap;
+        if let QueueExpiry::Ttl(ttl) = rcpt.expires {
+            rcpt.expires = QueueExpiry::Ttl(
+                ttl.saturating_sub(HOLD_SECONDS) + at.saturating_sub(message.created),
+            );
+        }
+        modified.insert(idx);
+    }
+    let saved = MessageWrapper::new(message, queue_id, QueueName::default())
+        .save_registry_changes(server, prev_events, modified)
+        .await;
+    held::delete(server.store(), queue_id).await?;
+    let _ = server.inner.ipc.queue_tx.send(QueueEvent::Refresh).await;
+    Ok(saved)
+}
+
+/// Takes a held message out of the queue and tells its sender, with the
+/// reviewer's note if there is one. False when it's no longer queued.
+pub async fn reject(server: &Server, record: &Held, note: Option<&str>) -> trc::Result<bool> {
+    let removed = match server
+        .read_message(record.queue_id, QueueName::default())
+        .await
+    {
+        Some(message) => message.remove(server, None).await,
+        None => false,
+    };
+    held::delete(server.store(), record.queue_id).await?;
+    let mut text = format!(
+        "Your message \"{}\" to {} was held for review under this server's rules, and wasn't sent.\r\n",
+        record.subject,
+        record.recipients.join(", ")
+    );
+    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"
+        )),
+    }
+    notify(
+        server,
+        record,
+        &format!("Not sent: {}", record.subject),
+        text,
+    )
+    .await;
+    let _ = server.inner.ipc.queue_tx.send(QueueEvent::Refresh).await;
+    Ok(removed)
+}
+
+/// Tells the sender their message is held (when the rule asks).
+pub async fn notify_held(server: &Server, record: &Held) {
+    let notices = record
+        .rules
+        .iter()
+        .map(|r| r.notice.as_str())
+        .collect::<Vec<_>>()
+        .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",
+        record.subject,
+        record.recipients.join(", "),
+    );
+    notify(
+        server,
+        record,
+        &format!("Held for review: {}", record.subject),
+        text,
+    )
+    .await;
+}
+
+async fn notify(server: &Server, record: &Held, subject: &str, text: String) {
+    let domain = record
+        .sender
+        .rsplit_once('@')
+        .map_or("localhost", |(_, d)| d);
+    let from = format!("postmaster@{domain}");
+    let message = MessageBuilder::new()
+        .from(Address::new_address(Some("Mail review"), from.clone()))
+        .to(Address::new_address(None::<String>, record.sender.clone()))
+        .subject(subject)
+        .header("Auto-Submitted", HeaderType::Text("auto-replied".into()))
+        .text_body(text)
+        .write_to_vec()
+        .unwrap_or_default();
+    server
+        .send_autogenerated(from, [record.sender.as_str()].into_iter(), message, None, 0)
+        .await;
+}
+
+/// Rejects every held message nobody reviewed in time (§2.6), each
+/// recorded as the server's doing. Returns how many.
+pub async fn expire(server: &Server) -> trc::Result<usize> {
+    let at = now();
+    let mut count = 0;
+    for record in held::all(server.store()).await? {
+        if !record.is_expired(at) {
+            continue;
+        }
+        reject(server, &record, None).await?;
+        count += 1;
+        server
+            .audit_note(Record {
+                at: at * 1000,
+                actor: Actor::system("DLP"),
+                via: None,
+                remote_ip: None,
+                action: Action::Destroy,
+                target: Target {
+                    kind: "inbuxa:HeldMessage".into(),
+                    id: Some(record.queue_id.to_string()),
+                    name: Some(record.subject.clone()),
+                    account_id: record.account_id,
+                    tenant_id: record.tenant_id,
+                },
+                changes: vec![],
+                details: Some(format!(
+                    "Rejected: nobody reviewed it within {KEEP_DAYS} days; the sender was told"
+                )),
+                reason: None,
+                outcome: Outcome::success(),
+            })
+            .await;
+    }
+    Ok(count)
+}

crates/smtp/src/queue/mod.rs

@@ -2,6 +2,8 @@
  * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ *
+ * Modified by Coffey Labs in 2026 for INBUXA.
  */
 
 use common::{
@@ -21,6 +23,7 @@ use types::blob_hash::BlobHash;
 use utils::DomainPart;
 
 pub mod dsn;
+pub mod held; // inbuxa: mail held for review
 pub mod manager;
 pub mod quota;
 pub mod spool;

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

@@ -293,8 +293,19 @@ once it's held (the webmail says so).
 Held messages count against no one's quota. Each held message and each
 decision is in the audit log.
 
-**Until phase 3** a hold rule blocks, with its notice, rather than let the
+**As built (phase 3).** Holding uses the queue's own future-release
-message through unreviewed.
+mechanism: the message is queued with its release a century off, every
+recipient's retry, notice and expiry pushed with it, so the stored format
+doesn't change. Release puts each recipient due now, keeps the gap to its
+next notice, and counts its lifetime from the release. The review record
+(`inbuxa:HeldMessage`, under `R` `h` + queue id) holds the sender,
+recipients, subject, size, rules and counts. Transport rules still apply to
+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.
 
 ### 2.7 What's recorded
 

resources/privacy/catalog.toml

@@ -79,6 +79,21 @@ lockedAt = ["metadata"]
 lockedBy = ["identifier"]
 delegates = ["identifier"]
 
+[object."inbuxa:HeldMessage"]
+file = "inbuxa_held_message.rs"
+default = "none"
+whose = ["holder", "correspondent"]
+where = ["data-store", "blob-store"]
+scope = "server"
+retention = "object-life"
+[object."inbuxa:HeldMessage".properties]
+sender = ["identifier", "contact"]
+recipients = ["identifier", "contact"]
+subject = ["content"]
+preview = ["content"]
+note = ["content"]
+counts = ["metadata"]
+
 [object."inbuxa:MailRule"]
 file = "inbuxa_mail_rule.rs"
 default = "none"

tests/src/system/mail_rules.rs

@@ -773,6 +773,329 @@ pub async fn transport(test: &mut TestServer) {
     call(&admin, "inbuxa:MailRule/set", json!({"destroy": transport})).await;
 }
 
+/// Hold for review (§2.6): held mail waits, shows in the review queue,
+/// can't be sent around the review, and a reviewer releases or rejects it.
+pub async fn hold(test: &mut TestServer) {
+    println!("Running held mail tests...");
+    let admin = test.account("[email protected]");
+    let sender = admin
+        .create_user_account(
+            "[email protected]",
+            "hold-sender-secret-7703",
+            "Hold sender",
+            &[],
+            vec![],
+        )
+        .await;
+    let (_, response) = call(
+        &sender,
+        "Identity/set",
+        json!({"create": {"i": {"name": "Sender", "email": "[email protected]"}}}),
+    )
+    .await;
+    let identity = response["created"]["i"]["id"].as_str().unwrap().to_string();
+    let (_, response) = call(
+        &sender,
+        "Mailbox/set",
+        json!({"create": {"m": {"name": "Hold drafts"}}}),
+    )
+    .await;
+    let mailbox = response["created"]["m"]["id"].as_str().unwrap().to_string();
+    let (_, response) = call(
+        &admin,
+        "inbuxa:MailRule/set",
+        json!({"create": {"h": {
+            "name": "Hold cards", "kind": "dlp", "direction": "outgoing",
+            "conditions": [{"type": "words", "words": ["hold-me"]},
+                {"type": "detected", "detectors": [{"id": "payment-card"}]}],
+            "actions": [{"type": "hold", "notice": "Card numbers are reviewed first.", "notifySender": true}]
+        }}}),
+    )
+    .await;
+    let rule = response["created"]["h"]["id"]
+        .as_str()
+        .unwrap_or_else(|| panic!("{response}"))
+        .to_string();
+    let body = "hold-me: card 4242 4242 4242 4242";
+
+    // Accepted, held, listed
+    let response = submit(
+        &sender,
+        &identity,
+        &mailbox,
+        &["[email protected]"],
+        "Held one",
+        body,
+        None,
+    )
+    .await;
+    let submission = response["created"]["s"]["id"]
+        .as_str()
+        .unwrap_or_else(|| panic!("held, not refused: {response}"))
+        .to_string();
+    let (_, response) = call(&admin, "inbuxa:HeldMessage/get", json!({"ids": null})).await;
+    let list = response["list"]
+        .as_array()
+        .unwrap_or_else(|| panic!("{response}"));
+    assert_eq!(list.len(), 1, "{response}");
+    let first = list[0]["id"].as_str().unwrap().to_string();
+    assert_eq!(list[0]["sender"], "[email protected]");
+    assert_eq!(list[0]["subject"], "Held one");
+    assert_eq!(list[0]["rules"][0]["name"], "Hold cards");
+    assert_eq!(
+        list[0]["counts"],
+        json!([{"detector": "words", "count": 1}, {"detector": "payment-card", "count": 1}])
+    );
+    assert!(
+        list[0].get("preview").is_none(),
+        "no preview unless asked for"
+    );
+
+    // The sender is told, and it isn't delivered
+    let notice = received(
+        &sender,
+        "Held for review: Held one",
+        "X-Flow",
+        Some(&mailbox),
+    )
+    .await;
+    assert!(
+        notice[0].1.contains("Card numbers are reviewed first."),
+        "{notice:?}"
+    );
+    assert!(
+        received_now(&sender, "Held one", &mailbox)
+            .await
+            .iter()
+            .all(|s| s.starts_with("Held for review"))
+    );
+
+    // Not around the review: not from the queue, not by unsending
+    let (_, response) = call(
+        &admin,
+        "x:QueuedMessage/set",
+        json!({"update": {first.as_str(): {"nextRetry": "2026-01-01T00:00:00Z"}}}),
+    )
+    .await;
+    assert!(
+        response["notUpdated"][first.as_str()]["description"]
+            .as_str()
+            .unwrap_or_default()
+            .contains("held for review"),
+        "{response}"
+    );
+    let (_, response) = call(&admin, "x:QueuedMessage/set", json!({"destroy": [first]})).await;
+    assert!(
+        response["notDestroyed"].get(first.as_str()).is_some(),
+        "{response}"
+    );
+    let (_, response) = call(
+        &sender,
+        "EmailSubmission/set",
+        json!({"update": {submission.as_str(): {"undoStatus": "canceled"}}}),
+    )
+    .await;
+    assert_eq!(
+        response["notUpdated"][submission.as_str()]["type"],
+        "cannotUnsend",
+        "{response}"
+    );
+
+    // Reading it is recorded
+    let (_, response) = call(
+        &admin,
+        "inbuxa:HeldMessage/get",
+        json!({"ids": [first], "properties": ["id", "preview"]}),
+    )
+    .await;
+    assert!(
+        response["list"][0]["preview"]
+            .as_str()
+            .unwrap_or_default()
+            .contains("4242 4242"),
+        "{response}"
+    );
+    let (_, response) = call(
+        &admin,
+        "inbuxa:AuditEvent/query",
+        json!({"filter": {"targetKind": "inbuxa:HeldMessage", "action": "blobAccess"}}),
+    )
+    .await;
+    assert_eq!(
+        response["ids"].as_array().map(|i| i.len()),
+        Some(1),
+        "{response}"
+    );
+
+    // Rejected: a reason is required; the sender gets the note
+    let (_, response) = call(
+        &admin,
+        "inbuxa:HeldMessage/set",
+        json!({"update": {first.as_str(): {"decision": "reject"}}}),
+    )
+    .await;
+    assert!(
+        response["notUpdated"].get(first.as_str()).is_some(),
+        "no reason: {response}"
+    );
+    let (_, response) = call(
+        &admin,
+        "inbuxa:HeldMessage/set",
+        json!({"reason": "Card data may not leave by mail", "update": {first.as_str(): {"decision": "reject", "note": "Use the payments portal."}}}),
+    )
+    .await;
+    assert!(
+        response["updated"].get(first.as_str()).is_some(),
+        "{response}"
+    );
+    let notice = received(&sender, "Not sent: Held one", "X-Flow", Some(&mailbox)).await;
+    assert!(
+        notice[0].1.contains("Use the payments portal."),
+        "{notice:?}"
+    );
+    let (_, response) = call(&admin, "x:QueuedMessage/get", json!({"ids": [first]})).await;
+    assert_eq!(
+        response["notFound"][0],
+        first.as_str(),
+        "gone from the queue: {response}"
+    );
+
+    // Released: delivered
+    let response = submit(
+        &sender,
+        &identity,
+        &mailbox,
+        &["[email protected]"],
+        "Held two",
+        body,
+        None,
+    )
+    .await;
+    assert!(response["created"].get("s").is_some(), "{response}");
+    let (_, response) = call(&admin, "inbuxa:HeldMessage/get", json!({"ids": null})).await;
+    let second = response["list"][0]["id"]
+        .as_str()
+        .unwrap_or_else(|| panic!("{response}"))
+        .to_string();
+    let (_, response) = call(
+        &admin,
+        "inbuxa:HeldMessage/set",
+        json!({"reason": "Finance approved", "update": {second.as_str(): {"decision": "release"}}}),
+    )
+    .await;
+    assert!(
+        response["updated"].get(second.as_str()).is_some(),
+        "{response}"
+    );
+    let mut delivered = Vec::new();
+    for _ in 0..50 {
+        delivered = received_now(&sender, "Held two", &mailbox).await;
+        if delivered.iter().any(|s| s == "Held two") {
+            break;
+        }
+        tokio::time::sleep(std::time::Duration::from_millis(200)).await;
+    }
+    assert!(delivered.iter().any(|s| s == "Held two"), "{delivered:?}");
+    let (_, response) = call(&admin, "inbuxa:HeldMessage/get", json!({"ids": null})).await;
+    assert_eq!(
+        response["list"].as_array().map(|l| l.len()),
+        Some(0),
+        "{response}"
+    );
+
+    // Both decisions are in the audit log, with their reasons
+    let (_, response) = call(
+        &admin,
+        "inbuxa:AuditEvent/query",
+        json!({"filter": {"targetKind": "inbuxa:HeldMessage", "action": "update"}}),
+    )
+    .await;
+    let ids = response["ids"].clone();
+    let (_, response) = call(&admin, "inbuxa:AuditEvent/get", json!({"ids": ids})).await;
+    let reasons: Vec<&str> = response["list"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .filter_map(|e| e["reason"].as_str())
+        .collect();
+    assert!(
+        reasons.contains(&"Card data may not leave by mail")
+            && reasons.contains(&"Finance approved"),
+        "{response}"
+    );
+
+    // Unreviewed: returned by the daily clean-up once its time is up
+    let response = submit(
+        &sender,
+        &identity,
+        &mailbox,
+        &["[email protected]"],
+        "Held three",
+        body,
+        None,
+    )
+    .await;
+    assert!(response["created"].get("s").is_some(), "{response}");
+    let store = test.server.store();
+    let mut record = inbuxa_features::mailflow::held::all(store)
+        .await
+        .unwrap()
+        .pop()
+        .expect("held");
+    record.expires_at = 0;
+    inbuxa_features::mailflow::held::create(store, &record)
+        .await
+        .unwrap();
+    assert_eq!(smtp::queue::held::expire(&test.server).await.unwrap(), 1);
+    assert!(
+        inbuxa_features::mailflow::held::all(store)
+            .await
+            .unwrap()
+            .is_empty()
+    );
+    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:?}"
+    );
+    let (_, response) = call(
+        &admin,
+        "inbuxa:AuditEvent/query",
+        json!({"filter": {"targetKind": "inbuxa:HeldMessage", "action": "destroy"}}),
+    )
+    .await;
+    assert_eq!(
+        response["ids"].as_array().map(|i| i.len()),
+        Some(1),
+        "expiry recorded: {response}"
+    );
+
+    call(&admin, "inbuxa:MailRule/set", json!({"destroy": [rule]})).await;
+}
+
+/// 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(
+        account,
+        "Email/query",
+        json!({"filter": {"subject": text, "inMailboxOtherThan": [drafts]}}),
+    )
+    .await;
+    let ids = response["ids"].clone();
+    let (_, response) = call(
+        account,
+        "Email/get",
+        json!({"ids": ids, "properties": ["subject"]}),
+    )
+    .await;
+    response["list"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .map(|e| e["subject"].as_str().unwrap_or_default().to_string())
+        .collect()
+}
+
 #[ignore]
 #[tokio::test(flavor = "multi_thread")]
 pub async fn mail_rules_tests() {
@@ -787,6 +1110,7 @@ pub async fn mail_rules_tests() {
     self::test(&mut test).await;
     self::dlp(&mut test).await;
     self::transport(&mut test).await;
+    self::hold(&mut test).await;
     if test.is_reset() {
         test.temp_dir.delete();
     }