diff --git a/src/api/mail_routes.py b/src/api/mail_routes.py
index d5483ba..17eb216 100644
--- a/src/api/mail_routes.py
+++ b/src/api/mail_routes.py
@@ -19,6 +19,23 @@ from src.blackboard.operations import Blackboard
 from src.blackboard.queries import Queries
 from src.utils import get_data_root
 
+
+def _get_valid_agents() -> set:
+    """从 config/default.yaml 读取有效 Agent ID 列表"""
+    config_path = Path(__file__).parent.parent / "config" / "default.yaml"
+    if config_path.exists():
+        import yaml
+        try:
+            with open(config_path) as f:
+                cfg = yaml.safe_load(f)
+            profiles = cfg.get("daemon", {}).get("agent_profiles", {})
+            if profiles:
+                return set(profiles.keys())
+        except Exception:
+            pass
+    # fallback：硬编码
+    return {"zhangfei-dev", "guanyu-dev", "zhaoyun-data", "jiangwei-infra", "pangtong-fujunshi", "simayi-challenger"}
+
 router = APIRouter(prefix="/api/mail", tags=["mail"])
 
 MAIL_PROJECT_ID = "_mail"