[问题] 关于将 Gmail 添加到本 SMTP 代理的问题

Hello, I have a question. At present, the WEB end has been configured to send and receive emails normally, but I am afraid that the messages on the mobile phone will not be timely, so I tried to add SMTP synchronization emails to Gmail. I referred to the official documentation, but I still don't understand the process very well. At present, Gmail must select one of the three ports provided to add it. Do I need to change the port mapping in Docker and then bind a domain name to connect normally?