Gmail错误：SMTP服务器需要安全连接或客户端未通过身份验证。服务器响应是：5.5.1需要验证

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required. Learn more at

https://www.google.com/settings/security/lesssecureapps https://myaccount.google.com/security#connectedapps 如果出现 5.5.1 Authentication Required 请打开此链接进行 启用 https://myaccount.google.com/security#connectedapps