在下一页上，确保将访问不太安全的应用程序设置为已启用。通过非Google应用程序发送SMTP要求这样做。

On the below page, make sure "Access for less secure apps" is set to Enabled. Sending SMTP through non-Google applications requires this.

https://www.google.com/settings/security

此外，请确保您在应用程序中启用了SSL。

Also, make sure you have SSL enabled in your application.