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/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)))