http://www.rfc-editor.org/rfc/rfc1939.txt
RFC 1939: Post Office Protocol - Version 3, J. Myers, M. Rose1996-05-01T23:00:00-00:00The Post Office Protocol - Version 3 (POP3) is intended to permit a workstation to dynamically access a maildrop on a server host in a useful fashion. [STANDARDS-TRACK]