diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69f09f2f..3c3dafb0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ If you are upgrading from v0.16.x, replace the binary (or run `docker pull`). If
   - Unchanged immutable `id` property is rejected on `/set`.
   - `filter: null` rejected as `notRequest` on `/query` and `/queryChanges`.
   - `Email/query` total miscount when `collapseThreads` is enabled.
+  - `SearchSnippet/get` response structure.
 - OIDC: Add default domain name to groups that are not email addresses.
 - RocksDB: Enable blob garbage collection to reclaim disk space from deleted blobs.
 
diff --git a/crates/jmap-proto/src/method/search_snippet.rs b/crates/jmap-proto/src/method/search_snippet.rs
index e6081c9e..70ddbe7a 100644
--- a/crates/jmap-proto/src/method/search_snippet.rs
+++ b/crates/jmap-proto/src/method/search_snippet.rs
@@ -33,8 +33,7 @@ pub struct GetSearchSnippetResponse {
     pub list: Vec<SearchSnippet>,
 
     #[serde(rename = "notFound")]
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub not_found: Vec<Id>,
+    pub not_found: Option<Vec<MaybeInvalid<Id>>>,
 }
 
 #[derive(serde::Serialize, Clone, Debug)]
@@ -42,10 +41,8 @@ pub struct SearchSnippet {
     #[serde(rename = "emailId")]
     pub email_id: Id,
 
-    #[serde(skip_serializing_if = "Option::is_none")]
     pub subject: Option<String>,
 
-    #[serde(skip_serializing_if = "Option::is_none")]
     pub preview: Option<String>,
 }
 
diff --git a/crates/jmap-proto/src/request/mod.rs b/crates/jmap-proto/src/request/mod.rs
index d2db6915..3b25284a 100644
--- a/crates/jmap-proto/src/request/mod.rs
+++ b/crates/jmap-proto/src/request/mod.rs
@@ -189,6 +189,18 @@ impl<'de, V: FromStr> serde::Deserialize<'de> for MaybeInvalid<V> {
     }
 }
 
+impl<V: FromStr + serde::Serialize> serde::Serialize for MaybeInvalid<V> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        match self {
+            MaybeInvalid::Value(v) => v.serialize(serializer),
+            MaybeInvalid::Invalid(s) => serializer.serialize_str(s),
+        }
+    }
+}
+
 impl<V: FromStr> Default for MaybeInvalid<V> {
     fn default() -> Self {
         MaybeInvalid::Invalid("".to_string())
diff --git a/crates/jmap/src/email/snippet.rs b/crates/jmap/src/email/snippet.rs
index 3628653a..0127abe7 100644
--- a/crates/jmap/src/email/snippet.rs
+++ b/crates/jmap/src/email/snippet.rs
@@ -17,7 +17,7 @@ use jmap_proto::{
         search_snippet::{GetSearchSnippetRequest, GetSearchSnippetResponse, SearchSnippet},
     },
     object::email::EmailFilter,
-    request::IntoValid,
+    request::MaybeInvalid,
 };
 use mail_parser::decoders::html::html_to_text;
 use nlp::language::{Language, search_snippet::generate_snippet, stemmer::Stemmer};
@@ -108,14 +108,22 @@ impl EmailSearchSnippet for Server {
         let mut response = GetSearchSnippetResponse {
             account_id: request.account_id,
             list: Vec::with_capacity(email_ids.len()),
-            not_found: vec![],
+            not_found: None,
         };
+        let mut not_found = Vec::new();
 
         if email_ids.len() > self.core.jmap.snippet_max_results {
             return Err(trc::JmapEvent::RequestTooLarge.into_err());
         }
 
-        for email_id in email_ids.into_valid() {
+        for email_id in email_ids {
+            let email_id = match email_id {
+                MaybeInvalid::Value(email_id) => email_id,
+                invalid => {
+                    not_found.push(invalid);
+                    continue;
+                }
+            };
             let document_id = email_id.document_id();
             let mut snippet = SearchSnippet {
                 email_id,
@@ -123,7 +131,7 @@ impl EmailSearchSnippet for Server {
                 preview: None,
             };
             if !document_ids.contains(document_id) {
-                response.not_found.push(email_id);
+                not_found.push(MaybeInvalid::Value(email_id));
                 continue;
             } else if terms.is_empty() {
                 response.list.push(snippet);
@@ -141,7 +149,7 @@ impl EmailSearchSnippet for Server {
             {
                 Some(metadata) => metadata,
                 None => {
-                    response.not_found.push(email_id);
+                    not_found.push(MaybeInvalid::Value(email_id));
                     continue;
                 }
             };
@@ -178,7 +186,7 @@ impl EmailSearchSnippet for Server {
                     CausedBy = trc::location!(),
                 );
 
-                response.not_found.push(email_id);
+                not_found.push(MaybeInvalid::Value(email_id));
                 continue;
             };
             let raw_message = ChainedBytes::new(metadata.raw_headers.as_ref()).with_last(
@@ -246,6 +254,10 @@ impl EmailSearchSnippet for Server {
             response.list.push(snippet);
         }
 
+        if !not_found.is_empty() {
+            response.not_found = Some(not_found);
+        }
+
         Ok(response)
     }
 }