Whenever you check for new mail, and whenever you see new messages being delivered to your computer, your computer is talking to the POP server. As with SMTP, you need to know the specific POP server address you are supposed to use to receive incoming e-mail. So, let's say that I know your POP server's address. Fortunately, the Post Office Protocol requires a username and password to communicate. If your e-mail program doesn't have your correct username and password, the POP server will reject your communication and you will be unable to receive new messages.
Some POP servers use even more robust security than just a username and password.
If this is the case with your POP server, then you may need to enable some advanced security options in your mail program. Menu question to me. Eudora already knows the four important pieces of information listed above. Now all you have to do is go back to your Web browser, find your e-mail settings and type in the settings. Again, the exact menu choices for these settings vary based on what Web browser you use, and sometimes they are a little difficult to find.