What is POP3 Email?
POP3 means “post office protocol, version 3″. It is a protocol for getting e-mail off of a web server. If you use Outlook Express, Outlook, Netscape Mail, or Eudora you’re using POP3.
Some web-based e-mail accounts use this protocol as well. I know that Hotmail and Yahoo (for a price) allow you to get your mail via POP3. AOL does not.