Source : Free On-Line Dictionary of Computing

POP3
     
         Version 3 of the {Post Office Protocol}.
        POP3 is defined in {RFC 1081}, written in November 1988 by
        Marshall Rose, which is based on RFC 918 (since revised as RFC
        937).  POP3 allows a {client} computer to retrieve {electronic
        mail} from a POP3 {server} via a (temporary) {TCP/IP} or
        other[?] connection.  It does not provide for sending mail,
        which is assumed to be done via {SMTP} or some other method.
     
        POP is useful for computers, e.g. mobile or home computers,
        without a permanent network connection which therefore require
        a "post office" (the POP server) to hold their mail until they
        can retrieve it.
     
        Although similar in form to the original POP proposed for the
        {Internet} community, POP3 is similar in spirit to the ideas
        investigated by the {MZnet} project at the University of
        California, Irvine, and is incompatible with earlier versions
        of POP.
     
        Substantial work was done on examining POP in a {PC}-based
        environment.  This work, which resulted in additional
        functionality in this protocol, was performed by the {ACIS}
        Networking Systems Group at {Stanford University}.
     
        RFC 1082 (POP3 Extended Service) extends POP3 to deal with
        accessing mailboxes for {mailing lists}.
     
        (1997-01-09)