POP3 stands for Post Office Protocol revision 3. This protocol handles the receiving of email messages from your mail server. It is important to know that if you access your email account via POP3, once your messages are download to your local computer, they are removed from the server. This makes it impractical if you would like to read your email on more than one place/computer. In such cases, we recommend that you setup to receive your mail via IMAP.