diff --git a/inventory-backend/app/utils/email_service.py b/inventory-backend/app/utils/email_service.py
index 3923180..b7a3d41 100644
--- a/inventory-backend/app/utils/email_service.py
+++ b/inventory-backend/app/utils/email_service.py
@@ -10,6 +10,7 @@ import logging
 from email.mime.text import MIMEText
 from email.mime.multipart import MIMEMultipart
 from email.header import Header
+from email.utils import formatdate, make_msgid
 from typing import List, Union
 
 logger = logging.getLogger(__name__)
@@ -94,6 +95,13 @@ def send_email(to_email: Union[str, List[str]], subject: str, content: str, cfg:
         msg['From']    = cfg['sender']
         msg['To']      = ', '.join(recipients)
         msg['Subject'] = Header(subject, 'utf-8')
+        # ★ Date 与 Message-ID 是 RFC 5322 的**必需/强烈建议**头，
+        #   smtplib 不会自动补。缺了它们，收件方的反垃圾引擎会显著加分
+        #   （"来源不明的自动化邮件"），很容易被判成垃圾或进隔离区 ——
+        #   而发件服务器照样回 250，客户端完全看不出来。
+        #   实测本项目的邮件此前两个头都没有。
+        msg['Date']       = formatdate(localtime=True)
+        msg['Message-ID'] = make_msgid(domain=(cfg['sender'].split('@')[-1] or None))
         msg.attach(MIMEText(content, 'plain', 'utf-8'))
 
         print(f"DEBUG: 准备向服务器提交发信请求，收件人: {recipients}  发件人: {cfg['username']}")