Couldn't reach server. Please double-check the server and port number

[Harsha Dilusha]

Unable to connect to SMTP Google server. Please double check the server and port number, I have added all the port numbers to the firewall

I've tried everything even whitelisting the IP on Google and the error persists

 

[cPanelWilliam]

Hello! I'd recommend double-checking the settings you have configured in the screenshot to see if they match the recommended settings within cPanel > Email Accounts > Connect Devices. Additionally, since you are using a secured connection I would recommend ensuring that the host you're connecting to has an SSL certificate installed. Lastly, you can also check the Exim log ( /var/log/exim_mainlog ) to see whether the connections from Gmail are making it to your server.

 

[xqm2023]

你好！我建议仔细检查您在屏幕截图中配置的设置，看看它们是否与 cPanel > 电子邮件帐户 > 连接设备中的推荐设置相匹配。此外，由于您使用的是安全连接，我建议您确保要连接的主机安装了 SSL 证书。最后，您还可以检查 Exim 日志 ( /var/log/exim_mainlog ) 以查看来自 Gmail 的连接是否正在连接到您的服务器。
[/引用]
我也遇到了这个问题，解决不了，提示COULDN'T Reach Server。请仔细检查服务器和端口号以及 535 错误的身份验证数据，CODE：535