我正在开发一个网站，在SMTP服务器上启用身份验证后，电子邮件停止工作。我安装了SMTP专业版扩展程序，并在运行自检时显示我
ASchroder.com SMTP Pro Self-test results
Testing outbound connectivity to Server:
Using SMTP configuration options
Connection to Host SMTP server successful.
Sending test email to your contact form address donotreply@example.com
Unable to send test email. Exception message was: Sender address is not valid for your login. Check your email program settings. ...
Please check and double check your username and password.
Contact Form test email used SMTPPro to send correctly.
Testing failed,
但是这个电子邮件地址适用于联系我们表格和有效的电子邮件地址。电子邮件正在联系我们表格，但不是忘记密码等。请指导我，以便我可以解决问题。谢谢