diff --git a/src/api/mail_routes.py b/src/api/mail_routes.py
index 7d42a29..34d67f3 100644
--- a/src/api/mail_routes.py
+++ b/src/api/mail_routes.py
@@ -171,17 +171,7 @@ async def update_mail(mail_id: str, body: Dict[str, Any]):
         if task.status not in ("done", "cancelled"):
             bb.update_task_status(mail_id, "done", agent="mail-api")
 
-    # 写回 must_haves
-    conn = bb._conn()
-    try:
-        conn.execute("BEGIN IMMEDIATE")
-        conn.execute(
-            "UPDATE tasks SET must_haves=?, updated_at=datetime('now') WHERE id=?",
-            (json.dumps(meta), mail_id),
-        )
-        conn.commit()
-    finally:
-        conn.close()
+    bb.update_must_haves(mail_id, json.dumps(meta))
 
     return {"ok": True}