{"message":"Email API Service","version":"2.0","endpoints":{"login":"POST /api/login - 用户登录获取 Token","send":"POST /api/send - 发送邮件（支持 API Key 或签名 Token）","verify":"POST /api/verify - 验证 Token 有效性"},"features":["✅ 多收件人支持","✅ 抄送（CC）和密送（BCC）","✅ HTML 和纯文本内容","✅ 自定义发件人名称","✅ 回复地址设置","✅ API Key 或 HMAC 签名 Token（更安全）"]}