diff --git a/CHANGELOG.md b/CHANGELOG.md
index 648005f6..605e5f59 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ If you are upgrading from v0.16.x, replace the binary (or run `docker pull`). If
   - Methods are only available if their capability is in `using`.
   - Reject requests that do not specify `application/json` in the `Content-Type` header.
   - Require `accountId` argument on requests.
+  - Return unparsable ids in `notFound` / `notUpdated` / `notDestroyed` / `notCopied` instead of dropping them.
   - Default calendars and address books are not subscribed by default.
   - `*/set`: Unchanged immutable `id` property is rejected on update.
   - `*/query` and `*/queryChanges`: null` rejected as `notRequest`.
diff --git a/crates/jmap-proto/src/method/copy.rs b/crates/jmap-proto/src/method/copy.rs
index 47eeb8cc..25d61d10 100644
--- a/crates/jmap-proto/src/method/copy.rs
+++ b/crates/jmap-proto/src/method/copy.rs
@@ -75,7 +75,7 @@ pub struct CopyBlobResponse {
 
     #[serde(rename = "notCopied")]
     #[serde(skip_serializing_if = "VecMap::is_empty")]
-    pub not_copied: VecMap<BlobId, SetError<BlobProperty>>,
+    pub not_copied: VecMap<MaybeInvalid<BlobId>, SetError<BlobProperty>>,
 }
 
 impl<'de, T: JmapObject> DeserializeArguments<'de> for CopyRequest<'de, T> {
diff --git a/crates/jmap-proto/src/method/get.rs b/crates/jmap-proto/src/method/get.rs
index b6cd707f..942ac336 100644
--- a/crates/jmap-proto/src/method/get.rs
+++ b/crates/jmap-proto/src/method/get.rs
@@ -7,7 +7,7 @@
 use crate::{
     object::JmapObject,
     request::{
-        IntoValid, MaybeInvalid,
+        MaybeInvalid,
         deserialize::{DeserializeArguments, deserialize_request},
         reference::{MaybeIdReference, MaybeResultReference, ResultReference},
     },
@@ -37,7 +37,13 @@ pub struct GetResponse<T: JmapObject> {
     pub list: Vec<Value<'static, T::Property, T::Element>>,
 
     #[serde(rename = "notFound")]
-    pub not_found: Vec<T::Id>,
+    pub not_found: Vec<MaybeInvalid<T::Id>>,
+}
+
+impl<T: JmapObject> GetResponse<T> {
+    pub fn push_not_found(&mut self, id: T::Id) {
+        self.not_found.push(MaybeInvalid::Value(id));
+    }
 }
 
 impl<'de, T: JmapObject> DeserializeArguments<'de> for GetRequest<T> {
@@ -116,16 +122,30 @@ impl<T: JmapObject> GetRequest<T> {
         }
     }
 
-    pub fn unwrap_ids(&mut self, max_objects_in_get: usize) -> trc::Result<Option<Vec<T::Id>>> {
+    #[allow(clippy::type_complexity)]
+    pub fn unwrap_ids(
+        &mut self,
+        max_objects_in_get: usize,
+    ) -> trc::Result<(Option<Vec<T::Id>>, Vec<MaybeInvalid<T::Id>>)> {
         if let Some(ids) = self.ids.take() {
             let ids = ids.unwrap();
             if ids.len() <= max_objects_in_get {
-                Ok(Some(ids.into_valid().collect::<Vec<_>>()))
+                let mut valid = Vec::with_capacity(ids.len());
+                let mut invalid = Vec::new();
+                for id in ids {
+                    match id {
+                        MaybeIdReference::Id(id) => valid.push(id),
+                        MaybeIdReference::Invalid(s) | MaybeIdReference::Reference(s) => {
+                            invalid.push(MaybeInvalid::Invalid(s))
+                        }
+                    }
+                }
+                Ok((Some(valid), invalid))
             } else {
                 Err(trc::JmapEvent::RequestTooLarge.into_err())
             }
         } else {
-            Ok(None)
+            Ok((None, Vec::new()))
         }
     }
 }
diff --git a/crates/jmap-proto/src/method/parse.rs b/crates/jmap-proto/src/method/parse.rs
index 71ce0869..ca0f2611 100644
--- a/crates/jmap-proto/src/method/parse.rs
+++ b/crates/jmap-proto/src/method/parse.rs
@@ -40,7 +40,7 @@ pub struct ParseResponse<T: JmapObject> {
 
     #[serde(rename = "notFound")]
     #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub not_found: Vec<BlobId>,
+    pub not_found: Vec<MaybeInvalid<BlobId>>,
 }
 
 impl<'de, T: JmapObject> DeserializeArguments<'de> for ParseRequest<T> {
diff --git a/crates/jmap-proto/src/method/set.rs b/crates/jmap-proto/src/method/set.rs
index 724be701..445f91f0 100644
--- a/crates/jmap-proto/src/method/set.rs
+++ b/crates/jmap-proto/src/method/set.rs
@@ -66,11 +66,11 @@ pub struct SetResponse<T: JmapObject> {
 
     #[serde(rename = "notUpdated")]
     #[serde(skip_serializing_if = "VecMap::is_empty")]
-    pub not_updated: VecMap<Id, SetError<T::Property>>,
+    pub not_updated: VecMap<MaybeInvalid<Id>, SetError<T::Property>>,
 
     #[serde(rename = "notDestroyed")]
     #[serde(skip_serializing_if = "VecMap::is_empty")]
-    pub not_destroyed: VecMap<Id, SetError<T::Property>>,
+    pub not_destroyed: VecMap<MaybeInvalid<Id>, SetError<T::Property>>,
 }
 
 impl<'de, T: JmapObject> DeserializeArguments<'de> for SetRequest<'de, T> {
@@ -211,6 +211,17 @@ impl<T: JmapObject> SetResponse<T> {
         self
     }
 
+    pub fn collect_will_destroy(&mut self, ids: Vec<MaybeInvalid<Id>>) -> Vec<Id> {
+        let mut will_destroy = Vec::with_capacity(ids.len());
+        for id in ids {
+            match id {
+                MaybeInvalid::Value(id) => will_destroy.push(id),
+                invalid => self.not_destroyed.append(invalid, SetError::not_found()),
+            }
+        }
+        will_destroy
+    }
+
     pub fn created(&mut self, id: String, document_id: impl Into<T::Id>) {
         self.created.insert(
             id,
diff --git a/crates/jmap-proto/src/object/calendar_event_notification.rs b/crates/jmap-proto/src/object/calendar_event_notification.rs
index 8e543245..64c2db3c 100644
--- a/crates/jmap-proto/src/object/calendar_event_notification.rs
+++ b/crates/jmap-proto/src/object/calendar_event_notification.rs
@@ -73,7 +73,13 @@ pub struct CalendarEventNotificationGetResponse {
     pub list: Vec<CalendarEventNotificationObject>,
 
     #[serde(rename = "notFound")]
-    pub not_found: Vec<Id>,
+    pub not_found: Vec<crate::request::MaybeInvalid<Id>>,
+}
+
+impl CalendarEventNotificationGetResponse {
+    pub fn push_not_found(&mut self, id: Id) {
+        self.not_found.push(crate::request::MaybeInvalid::Value(id));
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/crates/jmap-proto/src/request/mod.rs b/crates/jmap-proto/src/request/mod.rs
index 73ed18fd..42f6224e 100644
--- a/crates/jmap-proto/src/request/mod.rs
+++ b/crates/jmap-proto/src/request/mod.rs
@@ -214,6 +214,12 @@ impl<V: FromStr + serde::Serialize> serde::Serialize for MaybeInvalid<V> {
     }
 }
 
+impl<V: FromStr> From<V> for MaybeInvalid<V> {
+    fn from(value: V) -> Self {
+        MaybeInvalid::Value(value)
+    }
+}
+
 impl<V: FromStr> Default for MaybeInvalid<V> {
     fn default() -> Self {
         MaybeInvalid::Invalid("".to_string())
diff --git a/crates/jmap/src/addressbook/get.rs b/crates/jmap/src/addressbook/get.rs
index 2a775ff4..d8e6811f 100644
--- a/crates/jmap/src/addressbook/get.rs
+++ b/crates/jmap/src/addressbook/get.rs
@@ -38,7 +38,7 @@ impl AddressBookGet for Server {
         mut request: GetRequest<addressbook::AddressBook>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<addressbook::AddressBook>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             AddressBookProperty::Id,
             AddressBookProperty::Name,
@@ -92,14 +92,14 @@ impl AddressBookGet for Server {
             account_id: request.account_id.into(),
             state: cache.get_state(true).into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
             // Obtain the address_book object
             let document_id = id.document_id();
             if !address_book_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
             let _address_book = if let Some(address_book) = self
@@ -113,7 +113,7 @@ impl AddressBookGet for Server {
             {
                 address_book
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let address_book = _address_book
diff --git a/crates/jmap/src/addressbook/set.rs b/crates/jmap/src/addressbook/set.rs
index 77558fdd..3d1b6b30 100644
--- a/crates/jmap/src/addressbook/set.rs
+++ b/crates/jmap/src/addressbook/set.rs
@@ -16,7 +16,7 @@ use jmap_proto::{
     error::set::SetError,
     method::set::{SetRequest, SetResponse},
     object::addressbook::{self, AddressBookProperty, AddressBookValue},
-    request::{IntoValid, reference::MaybeIdReference},
+    request::{MaybeInvalid, reference::MaybeIdReference},
     types::state::State,
 };
 use jmap_tools::{JsonPointerItem, Key, Value};
@@ -59,7 +59,7 @@ impl AddressBookSet for Server {
             )
             .await?;
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let is_shared = access_token.is_shared(account_id);
         let mut set_default = None;
 
@@ -133,7 +133,14 @@ impl AddressBookSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/blob/copy.rs b/crates/jmap/src/blob/copy.rs
index 78f6c06d..0d79d093 100644
--- a/crates/jmap/src/blob/copy.rs
+++ b/crates/jmap/src/blob/copy.rs
@@ -9,7 +9,7 @@ use common::{Server, auth::AccessToken};
 use jmap_proto::{
     error::set::{SetError, SetErrorType},
     method::copy::{CopyBlobRequest, CopyBlobResponse},
-    request::IntoValid,
+    request::MaybeInvalid,
 };
 use registry::schema::enums::Permission;
 use std::future::Future;
@@ -40,7 +40,19 @@ impl BlobCopy for Server {
         };
         let account_id = request.account_id.document_id();
 
-        for blob_id in request.blob_ids.into_valid() {
+        for blob_id in request.blob_ids {
+            let blob_id = match blob_id {
+                MaybeInvalid::Value(blob_id) => blob_id,
+                invalid => {
+                    response.not_copied.append(
+                        invalid,
+                        SetError::new(SetErrorType::BlobNotFound).with_description(
+                            "blobId does not exist or not enough permissions to access it.",
+                        ),
+                    );
+                    continue;
+                }
+            };
             if self.has_access_blob(&blob_id, access_token).await? {
                 // Enforce quota
                 if !access_token.has_permission(Permission::UnlimitedUploads)
diff --git a/crates/jmap/src/blob/get.rs b/crates/jmap/src/blob/get.rs
index af902776..22b47f6e 100644
--- a/crates/jmap/src/blob/get.rs
+++ b/crates/jmap/src/blob/get.rs
@@ -47,9 +47,8 @@ impl BlobOperations for Server {
         mut request: GetRequest<Blob>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<Blob>> {
-        let ids = request
-            .unwrap_ids(self.core.jmap.get_max_objects)?
-            .unwrap_or_default();
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let ids = ids.unwrap_or_default();
         let properties = request.unwrap_properties(&[
             BlobProperty::Id,
             BlobProperty::Data(DataProperty::Default),
@@ -59,7 +58,7 @@ impl BlobOperations for Server {
             account_id: request.account_id.into(),
             state: None,
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         let range_from = request.arguments.offset.unwrap_or(0);
@@ -153,7 +152,7 @@ impl BlobOperations for Server {
                 // Add result to response
                 response.list.push(blob.into());
             } else {
-                response.not_found.push(blob_id);
+                response.push_not_found(blob_id);
             }
         }
 
diff --git a/crates/jmap/src/calendar/get.rs b/crates/jmap/src/calendar/get.rs
index d9edfad0..0d282263 100644
--- a/crates/jmap/src/calendar/get.rs
+++ b/crates/jmap/src/calendar/get.rs
@@ -45,7 +45,7 @@ impl CalendarGet for Server {
         mut request: GetRequest<calendar::Calendar>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<calendar::Calendar>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             CalendarProperty::Id,
             CalendarProperty::Name,
@@ -102,14 +102,14 @@ impl CalendarGet for Server {
             account_id: request.account_id.into(),
             state: cache.get_state(true).into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
             // Obtain the calendar object
             let document_id = id.document_id();
             if !calendar_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
             let _calendar = if let Some(calendar) = self
@@ -123,7 +123,7 @@ impl CalendarGet for Server {
             {
                 calendar
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let calendar = _calendar
diff --git a/crates/jmap/src/calendar/set.rs b/crates/jmap/src/calendar/set.rs
index 1969fef2..e536e667 100644
--- a/crates/jmap/src/calendar/set.rs
+++ b/crates/jmap/src/calendar/set.rs
@@ -21,7 +21,7 @@ use jmap_proto::{
     error::set::SetError,
     method::set::{SetRequest, SetResponse},
     object::calendar::{self, CalendarProperty, CalendarValue, IncludeInAvailability},
-    request::{IntoValid, reference::MaybeIdReference},
+    request::{MaybeInvalid, reference::MaybeIdReference},
     types::state::State,
 };
 use jmap_tools::{JsonPointerItem, Key, Map, Value};
@@ -64,7 +64,7 @@ impl CalendarSet for Server {
             )
             .await?;
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let is_shared = access_token.is_shared(account_id);
         let mut set_default = None;
 
@@ -138,7 +138,14 @@ impl CalendarSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/calendar_event/get.rs b/crates/jmap/src/calendar_event/get.rs
index 4c1775b2..58719777 100644
--- a/crates/jmap/src/calendar_event/get.rs
+++ b/crates/jmap/src/calendar_event/get.rs
@@ -213,7 +213,7 @@ impl CalendarEventGet for Server {
             // Obtain the calendar_event object
             let document_id = id.document_id();
             if !calendar_event_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
 
@@ -226,7 +226,7 @@ impl CalendarEventGet for Server {
                 ))
                 .await?
             else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let mut calendar_event = _calendar_event
@@ -290,7 +290,7 @@ impl CalendarEventGet for Server {
                 {
                     for expansion in expansions {
                         if !expansion.is_valid() {
-                            response.not_found.push(<Id as CalendarSyntheticId>::new(
+                            response.push_not_found(<Id as CalendarSyntheticId>::new(
                                 expansion.expansion_id,
                                 document_id,
                             ));
@@ -411,11 +411,12 @@ impl CalendarEventGet for Server {
                         ));
                     }
                 } else {
-                    response
-                        .not_found
-                        .extend(expansion_ids.into_iter().map(|expansion_id| {
-                            <Id as CalendarSyntheticId>::new(expansion_id, document_id)
-                        }));
+                    for expansion_id in expansion_ids {
+                        response.push_not_found(<Id as CalendarSyntheticId>::new(
+                            expansion_id,
+                            document_id,
+                        ));
+                    }
                     continue;
                 }
             }
diff --git a/crates/jmap/src/calendar_event/parse.rs b/crates/jmap/src/calendar_event/parse.rs
index 825bd8f6..b6507aa0 100644
--- a/crates/jmap/src/calendar_event/parse.rs
+++ b/crates/jmap/src/calendar_event/parse.rs
@@ -13,7 +13,7 @@ use common::{Server, auth::AccessToken};
 use jmap_proto::{
     method::parse::{ParseRequest, ParseResponse},
     object::calendar_event::CalendarEvent,
-    request::IntoValid,
+    request::{IntoValid, MaybeInvalid},
 };
 use jmap_tools::{Key, Value};
 use types::{blob::BlobId, id::Id};
@@ -54,7 +54,7 @@ impl CalendarEventParse for Server {
             let raw_vcard = match self.blob_download(&blob_id, access_token).await? {
                 Some(raw_vcard) => raw_vcard,
                 None => {
-                    response.not_found.push(blob_id);
+                    response.not_found.push(MaybeInvalid::Value(blob_id));
                     continue;
                 }
             };
diff --git a/crates/jmap/src/calendar_event/set.rs b/crates/jmap/src/calendar_event/set.rs
index cd93225a..b8690217 100644
--- a/crates/jmap/src/calendar_event/set.rs
+++ b/crates/jmap/src/calendar_event/set.rs
@@ -34,7 +34,7 @@ use jmap_proto::{
     error::set::SetError,
     method::set::{SetRequest, SetResponse},
     object::calendar_event,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::state::State,
 };
 use jmap_tools::{JsonPointerHandler, JsonPointerItem, Key, Map, Value};
@@ -97,7 +97,7 @@ impl CalendarEventSet for Server {
             .await
             .caused_by(trc::location!())?;
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
 
         // Obtain calendarIds
         let (can_add_calendars, can_delete_calendars, can_modify_calendars) =
@@ -146,7 +146,14 @@ impl CalendarEventSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/calendar_event_notification/get.rs b/crates/jmap/src/calendar_event_notification/get.rs
index 4edd15cb..e8a12e24 100644
--- a/crates/jmap/src/calendar_event_notification/get.rs
+++ b/crates/jmap/src/calendar_event_notification/get.rs
@@ -50,7 +50,7 @@ impl CalendarEventNotificationGet for Server {
         mut request: GetRequest<calendar_event_notification::CalendarEventNotification>,
         access_token: &AccessToken,
     ) -> trc::Result<CalendarEventNotificationGetResponse> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             CalendarEventNotificationProperty::Id,
             CalendarEventNotificationProperty::Created,
@@ -80,7 +80,7 @@ impl CalendarEventNotificationGet for Server {
             account_id: request.account_id.into(),
             state: cache.get_state(false).into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
@@ -97,7 +97,7 @@ impl CalendarEventNotificationGet for Server {
             {
                 event
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let event = _event
diff --git a/crates/jmap/src/contact/get.rs b/crates/jmap/src/contact/get.rs
index 0abcd8d6..533bf50f 100644
--- a/crates/jmap/src/contact/get.rs
+++ b/crates/jmap/src/contact/get.rs
@@ -41,7 +41,7 @@ impl ContactCardGet for Server {
         mut request: GetRequest<contact::ContactCard>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<contact::ContactCard>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let return_all_properties = request
             .properties
             .as_ref()
@@ -74,7 +74,7 @@ impl ContactCardGet for Server {
             account_id: request.account_id.into(),
             state: cache.get_state(false).into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
         let mut return_id = return_all_properties;
         let mut return_address_book_ids = return_all_properties;
@@ -101,7 +101,7 @@ impl ContactCardGet for Server {
             // Obtain the contact object
             let document_id = id.document_id();
             if !contact_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
 
@@ -116,7 +116,7 @@ impl ContactCardGet for Server {
             {
                 contact
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
 
diff --git a/crates/jmap/src/contact/parse.rs b/crates/jmap/src/contact/parse.rs
index 1679087c..bfd64a65 100644
--- a/crates/jmap/src/contact/parse.rs
+++ b/crates/jmap/src/contact/parse.rs
@@ -10,7 +10,7 @@ use common::{Server, auth::AccessToken};
 use jmap_proto::{
     method::parse::{ParseRequest, ParseResponse},
     object::contact::ContactCard,
-    request::IntoValid,
+    request::{IntoValid, MaybeInvalid},
 };
 use types::{blob::BlobId, id::Id};
 use utils::map::vec_map::VecMap;
@@ -50,7 +50,7 @@ impl ContactCardParse for Server {
             let raw_vcard = match self.blob_download(&blob_id, access_token).await? {
                 Some(raw_vcard) => raw_vcard,
                 None => {
-                    response.not_found.push(blob_id);
+                    response.not_found.push(MaybeInvalid::Value(blob_id));
                     continue;
                 }
             };
diff --git a/crates/jmap/src/contact/set.rs b/crates/jmap/src/contact/set.rs
index 97a3778c..0c6602e7 100644
--- a/crates/jmap/src/contact/set.rs
+++ b/crates/jmap/src/contact/set.rs
@@ -16,7 +16,7 @@ use jmap_proto::{
     error::set::SetError,
     method::set::{SetRequest, SetResponse},
     object::contact,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::state::State,
 };
 use jmap_tools::{JsonPointerHandler, JsonPointerItem, Key, Value};
@@ -73,7 +73,7 @@ impl ContactCardSet for Server {
             )
             .await?;
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
 
         // Obtain addressBookIds
         let (can_add_address_books, can_delete_address_books, can_modify_address_books) =
@@ -120,7 +120,14 @@ impl ContactCardSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/email/get.rs b/crates/jmap/src/email/get.rs
index b08aabd6..4577dfd1 100644
--- a/crates/jmap/src/email/get.rs
+++ b/crates/jmap/src/email/get.rs
@@ -55,7 +55,7 @@ impl EmailGet for Server {
         mut request: GetRequest<Email>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<Email>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             EmailProperty::Id,
             EmailProperty::BlobId,
@@ -131,7 +131,7 @@ impl EmailGet for Server {
             account_id: request.account_id.into(),
             state: cache.get_state(false).into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         // Check if we need to fetch the raw headers or body
@@ -153,7 +153,7 @@ impl EmailGet for Server {
         for id in ids {
             // Obtain the email object
             if !message_ids.contains(id.document_id()) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
             let metadata_ = match self
@@ -168,7 +168,7 @@ impl EmailGet for Server {
             {
                 Some(metadata) => metadata,
                 None => {
-                    response.not_found.push(id);
+                    response.push_not_found(id);
                     continue;
                 }
             };
@@ -180,7 +180,7 @@ impl EmailGet for Server {
             let data = match cache.email_by_id(&id.document_id()) {
                 Some(data) => data,
                 None => {
-                    response.not_found.push(id);
+                    response.push_not_found(id);
                     continue;
                 }
             };
@@ -212,7 +212,7 @@ impl EmailGet for Server {
                         CausedBy = trc::location!(),
                     );
 
-                    response.not_found.push(id);
+                    response.push_not_found(id);
                     continue;
                 }
             }
diff --git a/crates/jmap/src/email/parse.rs b/crates/jmap/src/email/parse.rs
index 6dd64c2e..d7f2fba5 100644
--- a/crates/jmap/src/email/parse.rs
+++ b/crates/jmap/src/email/parse.rs
@@ -14,11 +14,12 @@ use email::message::index::PREVIEW_LENGTH;
 use jmap_proto::{
     method::parse::{ParseRequest, ParseResponse},
     object::email::{Email, EmailProperty},
-    request::IntoValid,
+    request::{IntoValid, MaybeInvalid, reference::MaybeIdReference},
 };
 use jmap_tools::{Key, Map, Value};
 use mail_parser::{
-    MessageParser, PartType, decoders::html::html_to_text, parsers::preview::preview_text,
+    HeaderName, MessageParser, PartType, decoders::html::html_to_text,
+    parsers::preview::preview_text,
 };
 use std::future::Future;
 use utils::{chained_bytes::ChainedBytes, map::vec_map::VecMap};
@@ -97,20 +98,34 @@ impl EmailParse for Server {
             not_found: vec![],
         };
 
-        for blob_id in request.blob_ids.into_valid() {
+        for blob_id in request.blob_ids {
+            let blob_id = match blob_id {
+                MaybeIdReference::Id(blob_id) => blob_id,
+                MaybeIdReference::Invalid(s) | MaybeIdReference::Reference(s) => {
+                    response.not_found.push(MaybeInvalid::Invalid(s));
+                    continue;
+                }
+            };
             // Fetch raw message to parse
             let raw_message = match self.blob_download(&blob_id, access_token).await? {
                 Some(raw_message) => raw_message,
                 None => {
-                    response.not_found.push(blob_id);
+                    response.not_found.push(MaybeInvalid::Value(blob_id));
                     continue;
                 }
             };
-            let message = if let Some(message) = MessageParser::new().parse(&raw_message) {
+            let message = match MessageParser::new().parse(&raw_message).filter(|message| {
                 message
-            } else {
-                response.not_parsable.push(blob_id);
-                continue;
+                    .root_part()
+                    .headers()
+                    .iter()
+                    .any(|header| !matches!(header.name, HeaderName::Other(_)))
+            }) {
+                Some(message) => message,
+                None => {
+                    response.not_parsable.push(blob_id);
+                    continue;
+                }
             };
             let raw_message = ChainedBytes::new(&raw_message);
 
diff --git a/crates/jmap/src/email/set.rs b/crates/jmap/src/email/set.rs
index 34dbe5ed..414fb21c 100644
--- a/crates/jmap/src/email/set.rs
+++ b/crates/jmap/src/email/set.rs
@@ -28,7 +28,7 @@ use jmap_proto::{
     method::set::{SetRequest, SetResponse},
     object::email::{Email, EmailProperty, EmailValue},
     references::resolve::ResolveCreatedReference,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::state::State,
 };
 use jmap_tools::{Key, Value};
@@ -117,7 +117,7 @@ impl EmailSet for Server {
         };
 
         let mut last_change_id = None;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
 
         // Process creates
         'create: for (id, object) in request.unwrap_create() {
@@ -792,7 +792,14 @@ impl EmailSet for Server {
         let mut batch = BatchBuilder::new();
         let mut changed_mailboxes: AHashMap<u32, Vec<u32>> = AHashMap::new();
         let mut will_update = Vec::with_capacity(request.update.as_ref().map_or(0, |u| u.len()));
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/file/get.rs b/crates/jmap/src/file/get.rs
index 52a47720..6846b803 100644
--- a/crates/jmap/src/file/get.rs
+++ b/crates/jmap/src/file/get.rs
@@ -40,7 +40,7 @@ impl FileNodeGet for Server {
         mut request: GetRequest<file_node::FileNode>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<file_node::FileNode>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             FileNodeProperty::Id,
             FileNodeProperty::ParentId,
@@ -114,14 +114,14 @@ impl FileNodeGet for Server {
             account_id: request.account_id.into(),
             state: cache.get_state(false).into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
             // Obtain the file_node object
             let document_id = id.document_id();
             if !file_node_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
             let _file_node = if let Some(file_node) = self
@@ -135,7 +135,7 @@ impl FileNodeGet for Server {
             {
                 file_node
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let file_node = _file_node
diff --git a/crates/jmap/src/file/set.rs b/crates/jmap/src/file/set.rs
index bc2a9ee4..8f7190b0 100644
--- a/crates/jmap/src/file/set.rs
+++ b/crates/jmap/src/file/set.rs
@@ -19,7 +19,7 @@ use jmap_proto::{
         file_node::{self, FileNodeProperty, FileNodeValue, OnExists},
     },
     references::resolve::ResolveCreatedReference,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::state::State,
 };
 use jmap_tools::{JsonPointerItem, Key, Value};
@@ -68,7 +68,7 @@ impl FileNodeSet for Server {
             )
             .await?;
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let mut will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let mut will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let is_shared = access_token.is_shared(account_id);
         let on_destroy_remove_children = request
             .arguments
@@ -312,7 +312,14 @@ impl FileNodeSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) || implicit_destroys.contains(&id.document_id()) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/identity/get.rs b/crates/jmap/src/identity/get.rs
index d7350516..5a14e1a8 100644
--- a/crates/jmap/src/identity/get.rs
+++ b/crates/jmap/src/identity/get.rs
@@ -43,7 +43,7 @@ impl IdentityGet for Server {
         &self,
         mut request: GetRequest<identity::Identity>,
     ) -> trc::Result<GetResponse<identity::Identity>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             IdentityProperty::Id,
             IdentityProperty::Name,
@@ -72,14 +72,14 @@ impl IdentityGet for Server {
                 .await?
                 .into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
             // Obtain the identity object
             let document_id = id.document_id();
             if !identity_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
             let _identity = if let Some(identity) = self
@@ -93,7 +93,7 @@ impl IdentityGet for Server {
             {
                 identity
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let identity = _identity
diff --git a/crates/jmap/src/identity/set.rs b/crates/jmap/src/identity/set.rs
index 96e408d7..f52cd714 100644
--- a/crates/jmap/src/identity/set.rs
+++ b/crates/jmap/src/identity/set.rs
@@ -11,7 +11,7 @@ use jmap_proto::{
     method::set::{SetRequest, SetResponse},
     object::identity::{self, IdentityProperty, IdentityValue},
     references::resolve::ResolveCreatedReference,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::state::State,
 };
 use jmap_tools::{Key, Value};
@@ -46,7 +46,7 @@ impl IdentitySet for Server {
             .document_ids(account_id, Collection::Identity, IdentityField::DocumentId)
             .await?;
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let account_info = self
             .account_info(account_id)
             .await
@@ -131,7 +131,14 @@ impl IdentitySet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/mailbox/get.rs b/crates/jmap/src/mailbox/get.rs
index e4f19b58..5ec2ec30 100644
--- a/crates/jmap/src/mailbox/get.rs
+++ b/crates/jmap/src/mailbox/get.rs
@@ -31,7 +31,7 @@ impl MailboxGet for Server {
         mut request: GetRequest<Mailbox>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<Mailbox>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             MailboxProperty::Id,
             MailboxProperty::Name,
@@ -69,7 +69,7 @@ impl MailboxGet for Server {
             account_id: request.account_id.into(),
             state: Some(cache.mailboxes.change_id.into()),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
@@ -83,7 +83,7 @@ impl MailboxGet for Server {
                 }) {
                 mailbox
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
 
diff --git a/crates/jmap/src/mailbox/set.rs b/crates/jmap/src/mailbox/set.rs
index 8db63ae8..d4fc5667 100644
--- a/crates/jmap/src/mailbox/set.rs
+++ b/crates/jmap/src/mailbox/set.rs
@@ -25,7 +25,7 @@ use jmap_proto::{
     method::set::{SetRequest, SetResponse},
     object::mailbox::{self, MailboxProperty, MailboxValue},
     references::resolve::ResolveCreatedReference,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::state::State,
 };
 use jmap_tools::{JsonPointerItem, Key, Map, Value};
@@ -80,14 +80,16 @@ impl MailboxSet for Server {
         let account_id = request.account_id.document_id();
         let on_destroy_remove_emails = request.arguments.on_destroy_remove_emails.unwrap_or(false);
         let cache = self.get_cached_messages(account_id).await?;
+        let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?
+            .with_state(cache.assert_state(true, &request.if_in_state)?);
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let mut ctx = SetContext {
             account_id,
             is_shared: access_token.is_shared(account_id),
             access_token,
-            response: SetResponse::from_request(&request, self.core.jmap.set_max_objects)?
-                .with_state(cache.assert_state(true, &request.if_in_state)?),
+            response,
             mailbox_ids: RoaringBitmap::from_iter(cache.mailboxes.index.keys()),
-            will_destroy: request.unwrap_destroy().into_valid().collect(),
+            will_destroy,
         };
         let mut change_id = None;
         let account_info = self.account(account_id).await?;
@@ -161,7 +163,16 @@ impl MailboxSet for Server {
         // Process updates
         let mut will_update = Vec::with_capacity(request.update.as_ref().map_or(0, |u| u.len()));
         let mut batch = BatchBuilder::new();
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    ctx.response
+                        .not_updated
+                        .append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if ctx.will_destroy.contains(&id) {
                 ctx.response
diff --git a/crates/jmap/src/participant_identity/get.rs b/crates/jmap/src/participant_identity/get.rs
index 197557b8..00eb39a4 100644
--- a/crates/jmap/src/participant_identity/get.rs
+++ b/crates/jmap/src/participant_identity/get.rs
@@ -35,7 +35,7 @@ impl ParticipantIdentityGet for Server {
         &self,
         mut request: GetRequest<participant_identity::ParticipantIdentity>,
     ) -> trc::Result<GetResponse<participant_identity::ParticipantIdentity>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             ParticipantIdentityProperty::Id,
             ParticipantIdentityProperty::Name,
@@ -49,11 +49,13 @@ impl ParticipantIdentityGet for Server {
             account_id: request.account_id.into(),
             state: None,
             list: Vec::new(),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         let Some(identities) = identities else {
-            response.not_found = ids.unwrap_or_default();
+            for id in ids.unwrap_or_default() {
+                response.push_not_found(id);
+            }
             return Ok(response);
         };
 
@@ -76,7 +78,7 @@ impl ParticipantIdentityGet for Server {
             // Obtain the identity object
             let document_id = id.document_id();
             let Some(identity) = identities.identities.iter().find(|i| i.id == document_id) else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
 
diff --git a/crates/jmap/src/participant_identity/set.rs b/crates/jmap/src/participant_identity/set.rs
index 9dc3596c..5034be6d 100644
--- a/crates/jmap/src/participant_identity/set.rs
+++ b/crates/jmap/src/participant_identity/set.rs
@@ -11,7 +11,7 @@ use jmap_proto::{
     error::set::{SetError, SetErrorType},
     method::set::{SetRequest, SetResponse},
     object::participant_identity::{self, ParticipantIdentityProperty, ParticipantIdentityValue},
-    request::{IntoValid, reference::MaybeIdReference},
+    request::{MaybeInvalid, reference::MaybeIdReference},
 };
 use jmap_tools::{Key, Value};
 use registry::schema::prelude::StorageQuota;
@@ -38,7 +38,7 @@ impl ParticipantIdentitySet for Server {
     ) -> trc::Result<SetResponse<participant_identity::ParticipantIdentity>> {
         let account_id = request.account_id.document_id();
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let (identity_archive, mut identities) =
             match self.participant_identity_get_or_create(account_id).await? {
                 Some(archive) => {
@@ -127,7 +127,14 @@ impl ParticipantIdentitySet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/principal/get.rs b/crates/jmap/src/principal/get.rs
index 685e8346..0071e3da 100644
--- a/crates/jmap/src/principal/get.rs
+++ b/crates/jmap/src/principal/get.rs
@@ -39,7 +39,7 @@ impl PrincipalGet for Server {
                 .details("The administrator has disabled directory queries.".to_string()));
         }
 
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             PrincipalProperty::Id,
             PrincipalProperty::Type,
@@ -70,14 +70,14 @@ impl PrincipalGet for Server {
             account_id: request.account_id.into(),
             state: State::Initial.into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
             // Obtain the principal
             let document_id = id.document_id();
             if !principal_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let principal = self
diff --git a/crates/jmap/src/push/get.rs b/crates/jmap/src/push/get.rs
index fb8a3e8f..688642ef 100644
--- a/crates/jmap/src/push/get.rs
+++ b/crates/jmap/src/push/get.rs
@@ -35,7 +35,7 @@ impl PushSubscriptionFetch for Server {
         mut request: GetRequest<push_subscription::PushSubscription>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<push_subscription::PushSubscription>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             PushSubscriptionProperty::Id,
             PushSubscriptionProperty::DeviceClientId,
@@ -50,7 +50,7 @@ impl PushSubscriptionFetch for Server {
             account_id: request.account_id.into(),
             state: None,
             list: Vec::new(),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         let Some(subscriptions_) = self
@@ -64,7 +64,7 @@ impl PushSubscriptionFetch for Server {
             .await?
         else {
             for id in ids.unwrap_or_default() {
-                response.not_found.push(id);
+                response.push_not_found(id);
             }
             return Ok(response);
         };
@@ -93,7 +93,7 @@ impl PushSubscriptionFetch for Server {
                 .iter()
                 .find(|p| p.id.to_native() == document_id)
             else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
 
diff --git a/crates/jmap/src/push/set.rs b/crates/jmap/src/push/set.rs
index 8027e08b..5153dd19 100644
--- a/crates/jmap/src/push/set.rs
+++ b/crates/jmap/src/push/set.rs
@@ -12,7 +12,7 @@ use jmap_proto::{
     method::set::{SetRequest, SetResponse},
     object::push_subscription::{self, PushSubscriptionProperty, PushSubscriptionValue},
     references::resolve::ResolveCreatedReference,
-    request::IntoValid,
+    request::MaybeInvalid,
     types::date::UTCDate,
 };
 use jmap_tools::{Key, Map, Value};
@@ -76,7 +76,7 @@ impl PushSubscriptionSet for Server {
 
         // Prepare response
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
         let account = self.account(account_id).await.caused_by(trc::location!())?;
 
         // Process creates
@@ -154,7 +154,14 @@ impl PushSubscriptionSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response.not_updated.append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/quota/get.rs b/crates/jmap/src/quota/get.rs
index d4a1f89f..b06875cd 100644
--- a/crates/jmap/src/quota/get.rs
+++ b/crates/jmap/src/quota/get.rs
@@ -29,7 +29,7 @@ impl QuotaGet for Server {
         mut request: GetRequest<Quota>,
         access_token: &AccessToken,
     ) -> trc::Result<GetResponse<Quota>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             QuotaProperty::Id,
             QuotaProperty::ResourceType,
@@ -58,7 +58,7 @@ impl QuotaGet for Server {
             account_id: request.account_id.into(),
             state: State::Initial.into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         let account = if account_id == access_token.account_id() {
@@ -71,7 +71,7 @@ impl QuotaGet for Server {
             // Obtain the sieve script object
             let document_id = id.document_id();
             if !quota_ids.contains(&document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
 
diff --git a/crates/jmap/src/registry/get.rs b/crates/jmap/src/registry/get.rs
index 2860f0a9..ecd25a57 100644
--- a/crates/jmap/src/registry/get.rs
+++ b/crates/jmap/src/registry/get.rs
@@ -65,12 +65,13 @@ impl RegistryGet for Server {
             (object_flags & OBJ_FILTER_TENANT) != 0 && access_token.tenant_id().is_some();
         let is_account_filtered = (object_flags & OBJ_FILTER_ACCOUNT) != 0
             && !access_token.has_permission(Permission::Impersonate);
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let mut get = RegistryGetResponse {
             access_token,
             server: self,
             account_id: request.account_id.document_id(),
             object_type,
-            ids: request.unwrap_ids(self.core.jmap.get_max_objects)?,
+            ids,
             properties: request
                 .properties
                 .take()
@@ -83,7 +84,7 @@ impl RegistryGet for Server {
                 account_id: request.account_id.into(),
                 state: None,
                 list: vec![],
-                not_found: vec![],
+                not_found: not_found_ids,
             },
             object_flags,
             is_tenant_filtered,
@@ -233,7 +234,7 @@ impl RegistryGet for Server {
                         continue;
                     };
 
-                    let mut extra_properties = VecMap::new();
+                    let mut extra_properties: VecMap<Property, _> = VecMap::new();
                     match &object.inner {
                         ObjectInner::DkimSignature(obj)
                             if get.properties.is_empty()
@@ -384,11 +385,13 @@ impl RegistryGetResponse<'_> {
     }
 
     pub fn not_found(&mut self, id: Id) {
-        self.response.not_found.push(id);
+        self.response.push_not_found(id);
     }
 
     pub fn not_found_any(mut self) -> Self {
-        self.response.not_found = self.ids.take().unwrap_or_default();
+        for id in self.ids.take().unwrap_or_default() {
+            self.response.push_not_found(id);
+        }
         self
     }
 
diff --git a/crates/jmap/src/registry/mapping/account.rs b/crates/jmap/src/registry/mapping/account.rs
index ca8da8c6..ecd4139d 100644
--- a/crates/jmap/src/registry/mapping/account.rs
+++ b/crates/jmap/src/registry/mapping/account.rs
@@ -25,7 +25,7 @@ use common::{
     ipc::CacheInvalidation,
 };
 use directory::core::secret::{SecretVerificationResult, hash_secret, verify_mfa_secret_hash};
-use jmap_proto::{error::set::SetError, types::state::State};
+use jmap_proto::{error::set::SetError, request::MaybeInvalid, types::state::State};
 use jmap_tools::{JsonPointer, JsonPointerItem, Key, Map, Value};
 use registry::{
     jmap::{IntoValue, JsonPointerPatch, MaybeUnpatched, RegistryJsonPatch, RegistryValue},
@@ -646,13 +646,13 @@ pub(crate) async fn account_set(
                     .response
                     .updated
                     .into_keys()
-                    .map(|id| (id, err.clone()))
+                    .map(|id| (MaybeInvalid::Value(id), err.clone()))
                     .collect::<Vec<_>>();
                 let failed_delete = set
                     .response
                     .destroyed
                     .into_iter()
-                    .map(|id| (id, err.clone()))
+                    .map(|id| (MaybeInvalid::Value(id), err.clone()))
                     .collect::<Vec<_>>();
 
                 set.response.not_created.extend(failed_create);
@@ -706,7 +706,7 @@ pub(crate) async fn account_get(
                 }
             }
 
-            get.response.not_found.extend(ids);
+            get.response.not_found.extend(ids.map(MaybeInvalid::Value));
         }
         ObjectType::AccountPassword => {
             let mut ids = get
@@ -747,7 +747,7 @@ pub(crate) async fn account_get(
                 }
             }
 
-            get.response.not_found.extend(ids);
+            get.response.not_found.extend(ids.map(MaybeInvalid::Value));
         }
         ObjectType::ApiKey | ObjectType::AppPassword => {
             let mut ids = if let Some(ids) = get.ids.take() {
diff --git a/crates/jmap/src/registry/mapping/bootstrap.rs b/crates/jmap/src/registry/mapping/bootstrap.rs
index 06f7ff50..351f81c9 100644
--- a/crates/jmap/src/registry/mapping/bootstrap.rs
+++ b/crates/jmap/src/registry/mapping/bootstrap.rs
@@ -13,7 +13,10 @@ use common::{
     network::acme::account::acme_create_account, psl,
 };
 use directory::core::secret::hash_secret;
-use jmap_proto::error::set::{SetError, SetErrorType};
+use jmap_proto::{
+    error::set::{SetError, SetErrorType},
+    request::MaybeInvalid,
+};
 use jmap_tools::{JsonPointer, JsonPointerItem, Key};
 use rand::{Rng, distr::Alphanumeric, rng};
 use registry::{
@@ -67,7 +70,7 @@ pub(crate) async fn bootstrap_get(
         }
     }
 
-    get.response.not_found.extend(ids);
+    get.response.not_found.extend(ids.map(MaybeInvalid::Value));
     Ok(get)
 }
 
diff --git a/crates/jmap/src/registry/set.rs b/crates/jmap/src/registry/set.rs
index 7bdf46ae..46399da0 100644
--- a/crates/jmap/src/registry/set.rs
+++ b/crates/jmap/src/registry/set.rs
@@ -38,7 +38,7 @@ use jmap_proto::{
     method::set::{SetRequest, SetResponse},
     object::registry::Registry,
     references::resolve::ResolveCreatedReference,
-    request::IntoValid,
+    request::{IntoValid, MaybeInvalid},
 };
 use jmap_tools::{JsonPointer, JsonPointerItem, Key};
 use registry::{
@@ -125,9 +125,11 @@ impl RegistrySet for Server {
         // Initial destroy validation for singletons
         let mut destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
         if is_singleton && !destroy.is_empty() {
-            response
-                .not_destroyed
-                .extend(destroy.drain(..).map(|id| (id, SetError::singleton())));
+            response.not_destroyed.extend(
+                destroy
+                    .drain(..)
+                    .map(|id| (MaybeInvalid::Value(id), SetError::singleton())),
+            );
         }
 
         // Update validation for willDestroy
diff --git a/crates/jmap/src/share_notification/get.rs b/crates/jmap/src/share_notification/get.rs
index 076ec039..a9da1f24 100644
--- a/crates/jmap/src/share_notification/get.rs
+++ b/crates/jmap/src/share_notification/get.rs
@@ -172,9 +172,9 @@ impl ShareNotificationGet for Server {
             response.state = Some(State::Initial);
         }
 
-        response
-            .not_found
-            .extend(ids.into_iter().map(Id::from).collect::<Vec<_>>());
+        for id in ids {
+            response.push_not_found(Id::from(id));
+        }
 
         Ok(response)
     }
diff --git a/crates/jmap/src/sieve/get.rs b/crates/jmap/src/sieve/get.rs
index bb5d524a..7abda923 100644
--- a/crates/jmap/src/sieve/get.rs
+++ b/crates/jmap/src/sieve/get.rs
@@ -36,7 +36,7 @@ impl SieveScriptGet for Server {
         &self,
         mut request: GetRequest<Sieve>,
     ) -> trc::Result<GetResponse<Sieve>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             SieveProperty::Id,
             SieveProperty::Name,
@@ -63,7 +63,7 @@ impl SieveScriptGet for Server {
                 .await?
                 .into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
         let active_script_id = self.sieve_script_get_active_id(account_id).await?;
 
@@ -71,7 +71,7 @@ impl SieveScriptGet for Server {
             // Obtain the sieve script object
             let document_id = id.document_id();
             if !script_ids.contains(document_id) {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             }
             let sieve_ = if let Some(sieve) = self
@@ -85,7 +85,7 @@ impl SieveScriptGet for Server {
             {
                 sieve
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let sieve = sieve_
diff --git a/crates/jmap/src/sieve/set.rs b/crates/jmap/src/sieve/set.rs
index e8cc2d5a..3132eb2e 100644
--- a/crates/jmap/src/sieve/set.rs
+++ b/crates/jmap/src/sieve/set.rs
@@ -19,7 +19,7 @@ use jmap_proto::{
     method::set::{SetRequest, SetResponse},
     object::sieve::{Sieve, SieveProperty, SieveValue},
     references::resolve::ResolveCreatedReference,
-    request::{IntoValid, reference::MaybeIdReference},
+    request::{MaybeInvalid, reference::MaybeIdReference},
     types::state::State,
 };
 use jmap_tools::{Key, Map, Value};
@@ -91,7 +91,7 @@ impl SieveScriptSet for Server {
                     .await?,
                 ),
         };
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = ctx.response.collect_will_destroy(request.unwrap_destroy());
 
         // Validate active script id
         if let Some(MaybeIdReference::Id(id)) = &request.arguments.on_success_activate_script
@@ -197,7 +197,16 @@ impl SieveScriptSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    ctx.response
+                        .not_updated
+                        .append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 ctx.response
diff --git a/crates/jmap/src/submission/get.rs b/crates/jmap/src/submission/get.rs
index 5153783c..90a538bd 100644
--- a/crates/jmap/src/submission/get.rs
+++ b/crates/jmap/src/submission/get.rs
@@ -46,7 +46,7 @@ impl EmailSubmissionGet for Server {
         &self,
         mut request: GetRequest<email_submission::EmailSubmission>,
     ) -> trc::Result<GetResponse<email_submission::EmailSubmission>> {
-        let ids = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
         let properties = request.unwrap_properties(&[
             EmailSubmissionProperty::Id,
             EmailSubmissionProperty::EmailId,
@@ -107,7 +107,7 @@ impl EmailSubmissionGet for Server {
                 .await?
                 .into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         for id in ids {
@@ -124,7 +124,7 @@ impl EmailSubmissionGet for Server {
             {
                 submission
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
                 continue;
             };
             let submission = submission_
diff --git a/crates/jmap/src/submission/set.rs b/crates/jmap/src/submission/set.rs
index eab2fa18..99f099f7 100644
--- a/crates/jmap/src/submission/set.rs
+++ b/crates/jmap/src/submission/set.rs
@@ -21,7 +21,7 @@ use jmap_proto::{
     object::email_submission::{self, EmailSubmissionProperty, EmailSubmissionValue},
     references::resolve::ResolveCreatedReference,
     request::{
-        Call, IntoValid, MaybeInvalid, RequestMethod, SetRequestMethod,
+        Call, MaybeInvalid, RequestMethod, SetRequestMethod,
         method::{MethodFunction, MethodName, MethodObject},
         reference::{MaybeIdReference, MaybeResultReference},
     },
@@ -71,7 +71,7 @@ impl EmailSubmissionSet for Server {
     ) -> trc::Result<SetResponse<email_submission::EmailSubmission>> {
         let account_id = request.account_id.document_id();
         let mut response = SetResponse::from_request(&request, self.core.jmap.set_max_objects)?;
-        let will_destroy = request.unwrap_destroy().into_valid().collect::<Vec<_>>();
+        let will_destroy = response.collect_will_destroy(request.unwrap_destroy());
 
         // Process creates
         let mut success_email_ids = HashMap::new();
@@ -137,7 +137,16 @@ impl EmailSubmissionSet for Server {
         }
 
         // Process updates
-        'update: for (id, object) in request.unwrap_update().into_valid() {
+        'update: for (id, object) in request.unwrap_update() {
+            let id = match id {
+                MaybeInvalid::Value(id) => id,
+                invalid => {
+                    response
+                        .not_updated
+                        .append(invalid, SetError::not_found());
+                    continue 'update;
+                }
+            };
             // Make sure id won't be destroyed
             if will_destroy.contains(&id) {
                 response.not_updated.append(id, SetError::will_destroy());
diff --git a/crates/jmap/src/thread/get.rs b/crates/jmap/src/thread/get.rs
index 75599c33..654b1b1a 100644
--- a/crates/jmap/src/thread/get.rs
+++ b/crates/jmap/src/thread/get.rs
@@ -63,7 +63,8 @@ impl ThreadGet for Server {
             all_ids.insert(item.document_id);
         }
 
-        let ids = if let Some(ids) = request.unwrap_ids(self.core.jmap.get_max_objects)? {
+        let (ids, not_found_ids) = request.unwrap_ids(self.core.jmap.get_max_objects)?;
+        let ids = if let Some(ids) = ids {
             ids
         } else {
             thread_map
@@ -84,7 +85,7 @@ impl ThreadGet for Server {
                 .await?
                 .into(),
             list: Vec::with_capacity(ids.len()),
-            not_found: vec![],
+            not_found: not_found_ids,
         };
 
         let ordered_ids = if add_email_ids && !all_ids.is_empty() {
@@ -125,7 +126,7 @@ impl ThreadGet for Server {
                 }
                 response.list.push(thread.into());
             } else {
-                response.not_found.push(id);
+                response.push_not_found(id);
             }
         }
 
diff --git a/crates/jmap/src/vacation/get.rs b/crates/jmap/src/vacation/get.rs
index 45140103..ab2b8ef0 100644
--- a/crates/jmap/src/vacation/get.rs
+++ b/crates/jmap/src/vacation/get.rs
@@ -12,7 +12,10 @@ use jmap_proto::{
     object::vacation_response::{
         VacationResponse, VacationResponseProperty, VacationResponseValue,
     },
-    request::reference::MaybeResultReference,
+    request::{
+        MaybeInvalid,
+        reference::{MaybeIdReference, MaybeResultReference},
+    },
     types::date::UTCDate,
 };
 use jmap_tools::{Map, Value};
@@ -68,14 +71,16 @@ impl VacationResponseGet for Server {
         let do_get = if let Some(MaybeResultReference::Value(ids)) = request.ids {
             let mut do_get = false;
             for id in ids {
-                match id.try_unwrap() {
-                    Some(id) if id.is_singleton() => {
+                match id {
+                    MaybeIdReference::Id(id) if id.is_singleton() => {
                         do_get = true;
                     }
-                    Some(id) => {
-                        response.not_found.push(id);
+                    MaybeIdReference::Id(id) => {
+                        response.push_not_found(id);
+                    }
+                    MaybeIdReference::Invalid(s) | MaybeIdReference::Reference(s) => {
+                        response.not_found.push(MaybeInvalid::Invalid(s));
                     }
-                    _ => {}
                 }
             }
             do_get
diff --git a/crates/utils/src/map/vec_map.rs b/crates/utils/src/map/vec_map.rs
index 3b5c7845..67b42b43 100644
--- a/crates/utils/src/map/vec_map.rs
+++ b/crates/utils/src/map/vec_map.rs
@@ -41,7 +41,8 @@ impl<K: Eq + PartialEq, V> VecMap<K, V> {
     }
 
     #[inline(always)]
-    pub fn set(&mut self, key: K, value: V) -> bool {
+    pub fn set(&mut self, key: impl Into<K>, value: V) -> bool {
+        let key = key.into();
         if let Some(kv) = self.inner.iter_mut().find(|kv| kv.key == key) {
             kv.value = value;
             false
@@ -52,19 +53,28 @@ impl<K: Eq + PartialEq, V> VecMap<K, V> {
     }
 
     #[inline(always)]
-    pub fn append(&mut self, key: K, value: V) {
-        self.inner.push(KeyValue { key, value });
+    pub fn append(&mut self, key: impl Into<K>, value: V) {
+        self.inner.push(KeyValue {
+            key: key.into(),
+            value,
+        });
     }
 
     #[inline(always)]
-    pub fn with_append(mut self, key: K, value: V) -> Self {
+    pub fn with_append(mut self, key: impl Into<K>, value: V) -> Self {
         self.append(key, value);
         self
     }
 
     #[inline(always)]
-    pub fn insert(&mut self, idx: usize, key: K, value: V) {
-        self.inner.insert(idx, KeyValue { key, value });
+    pub fn insert(&mut self, idx: usize, key: impl Into<K>, value: V) {
+        self.inner.insert(
+            idx,
+            KeyValue {
+                key: key.into(),
+                value,
+            },
+        );
     }
 
     #[inline(always)]