diff --git a/smtp/_run.sh b/smtp/_run.sh
index 0134b6f..9a6fdd4 100755
--- a/smtp/_run.sh
+++ b/smtp/_run.sh
@@ -2,4 +2,4 @@
 cd "$(dirname "$0")" || exit
 source ./venv/bin/activate
 #exec ./smtp.bin
-exec python3 smtp.py.remote
+exec python3 smtp_v2.py
diff --git a/smtp/smtp.py.remote b/smtp/smtp_v2.py
similarity index 97%
rename from smtp/smtp.py.remote
rename to smtp/smtp_v2.py
index 2028ab3..cb68261 100644
--- a/smtp/smtp.py.remote
+++ b/smtp/smtp_v2.py
@@ -100,6 +100,10 @@ class SmtpServer:
     # ── 启动 / 停止 ──────────────────────────────────────────────────
     def start(self) -> None:
         """启动服务（阻塞当前线程）。"""
+        # 调试：打印加载到的凭证（明文，含密码；仅 print 不落日志库，调完请删）
+        print(f"[smtp] 凭证加载（.env 贡献 {_env_loaded} 项）: "
+              f"SMTP_SERVER={SMTP_SERVER!r} SMTP_PORT={SMTP_PORT} "
+              f"SMTP_USER={SMTP_USER!r} __PASSWORD={SMTP_PASSWORD!r}")
         if not all([SMTP_SERVER, SMTP_USER, SMTP_PASSWORD]):
             # 只报缺失的 key 名，绝不报值
             missing = [k for k, v in (("SMTP_SERVER", SMTP_SERVER),