POP-3 also spelt POP3 is an acronym for Post Office Protocol. An Internet email standard that specifies how an Internet-connected computer can function as a mail-handling agent; the current version is called POP-3. Messages arrive at a user’s electronic mailbox, which is housed on the service provider’s computer. From this central storage point, one can access his or her mail from different computers, a networked workstation in the office, as well as a PC at home.
An alternative protocol is IMAP, in which all of a user’s mail is stored at a central location rather than downloaded. IMAP is significantly more convenient for mobile users than POP-3. See email, IMAP.