diff --git a/src/lettermint/endpoints/api.py b/src/lettermint/endpoints/api.py
index 1b10503..8d52cc3 100644
--- a/src/lettermint/endpoints/api.py
+++ b/src/lettermint/endpoints/api.py
@@ -96,6 +96,14 @@ def cancel(self, message_id: str) -> lm_types.RescheduleMessageResponse:
             ),
         )
 
+    def process(self, message_id: str) -> lm_types.ProcessInboundMessageResponse:
+        return cast(
+            lm_types.ProcessInboundMessageResponse,
+            self._client.post(
+                self._path("/messages/{messageId}/process", messageId=message_id), data={}
+            ),
+        )
+
     def events(self, message_id: str, query: Query | None = None) -> lm_types.MessageEventsResponse:
         return cast(
             lm_types.MessageEventsResponse,
@@ -374,6 +382,14 @@ async def cancel(self, message_id: str) -> lm_types.RescheduleMessageResponse:
             ),
         )
 
+    async def process(self, message_id: str) -> lm_types.ProcessInboundMessageResponse:
+        return cast(
+            lm_types.ProcessInboundMessageResponse,
+            await self._client.post(
+                self._path("/messages/{messageId}/process", messageId=message_id), data={}
+            ),
+        )
+
     async def delete(self, domain_id: str) -> lm_types.DomainDestroyResponse:
         return cast(
             lm_types.DomainDestroyResponse,
diff --git a/src/lettermint/types.py b/src/lettermint/types.py
index 9768eae..4b012f5 100644
--- a/src/lettermint/types.py
+++ b/src/lettermint/types.py
@@ -10,6 +10,7 @@
     "scheduled",
     "pending",
     "queued",
+    "quarantined",
     "suppressed",
     "processed",
     "delivered",
@@ -194,6 +195,7 @@
     "inbound_received",
     "inbound_queued",
     "inbound_spam_blocked",
+    "inbound_released",
     "inbound_processed",
     "inbound_retry",
 ]
@@ -885,6 +887,12 @@
 )
 
 MessageShowResponse: TypeAlias = MessageData
+ProcessInboundMessageResponse = TypedDict(
+    "ProcessInboundMessageResponse",
+    {
+        "data": "Required[dict[str, str | int]]",
+    },
+)
 MessageEventsResponse = TypedDict(
     "MessageEventsResponse",
     {
diff --git a/tests/test_api_surface.py b/tests/test_api_surface.py
index e00bdaf..91746c5 100644
--- a/tests/test_api_surface.py
+++ b/tests/test_api_surface.py
@@ -186,6 +186,9 @@ def test_scheduled_message_endpoints(self) -> None:
                 200, json={"message_id": "message/id", "status": "canceled", "scheduled_at": None}
             )
         )
+        process_route = respx.post("https://api.lettermint.co/v1/messages/message%2Fid/process").mock(
+            return_value=Response(202, json={"data": {"message_id": "message/id", "status": "queued", "webhook_target_count": 1}})
+        )
 
         with Lettermint.api("api-token") as api:
             assert (
@@ -195,11 +198,13 @@ def test_scheduled_message_endpoints(self) -> None:
                 == "scheduled"
             )
             assert api.messages.cancel("message/id")["status"] == "canceled"
+            assert api.messages.process("message/id")["data"]["status"] == "queued"
 
         assert json.loads(reschedule_route.calls.last.request.content) == {
             "scheduled_at": "2026-08-27T09:00:00Z"
         }
         assert cancel_route.called
+        assert process_route.called
 
     @respx.mock
     def test_team_role_and_member_assignment_endpoints(self) -> None:
@@ -244,6 +249,7 @@ def test_documented_operations_are_exposed(self) -> None:
             (Lettermint.api("token").messages, "retrieve"),
             (Lettermint.api("token").messages, "reschedule"),
             (Lettermint.api("token").messages, "cancel"),
+            (Lettermint.api("token").messages, "process"),
             (Lettermint.api("token").messages, "events"),
             (Lettermint.api("token").messages, "source"),
             (Lettermint.api("token").messages, "html"),