Post Office Protocol (POP), an application-layer internet standard protocol used by local email clients to retrieve email from a remote server over a TCP/IP connection, was specified and a proposed to be the protocol for the ARPA-Internet community.
The intent of POP is to allow a user's to access mail from a mailbox server. It was expected that mail will be posted from the workstation to the mailbox server via the Simple Mail Transfer Protocol (SMTP).
Currently, virtually all email clients and servers support POP, and IMAP (Internet Message Access Protocol). They're the two most prevalent internet standard protocols for email retrieval.
