POP3

The Post Office Protocol version 3, or POP3, is the newest iteration of a protocol—or set of software rules—that allows a user to receive email from the Internet. The basic functionality is such that a server receives and holds an email message that waits for a client computer to connect and download the message to a mail-reading application.

This protocol is implemented in all of the most popular and widely used email clients, such as Eudora and Microsoft Outlook Express. Increasingly, web-based email services also allow POP3 client applications to access the remotely resident email and view it in the application window as if it were standard email.

One drawback of POP3 is that it is designed to delete email on the server after the user has downloaded the information. With limitations, this can be delayed, but it is a part of the POP3.

An alternative to this is the IMAP, which affords users more flexibility in storage or deletion of electronic mail.