The pop-login method referred to the remote login method using the personal pop3 port. In the email protocol, POP3 was a protocol used to download email content from a mail server and save it to a local computer. When logging in with POP3, you need to set the mail server as a POP3-capable server and have the corresponding authority. In Web development, the POP login method is usually used to download mail content from the mail server to the local computer. In the Web application, you can use the POP3 protocol to log into the mail server and download the mail content. Usually, you need to set up a POP3 port in your Web application to download mail content from the mail server.