RFC 1225 (rfc1225) - Page 1 of 16

Post Office Protocol: Version 3

Network Working Group                                            M. Rose
Request for Comments: 1225             Performance Systems International
Obsoletes: RFC 1081                                             May 1991


                    Post Office Protocol - Version 3

Status of this Memo

   This memo suggests a simple method for workstations to dynamically
   access mail from a mailbox server.  This RFC specifies an IAB
   standards track protocol for the Internet community, and requests
   discussion and suggestions for improvements.  Please refer to the
   current edition of the "IAB Official Protocol Standards" for the
   standardization state and status of this protocol.  Distribution of
   this memo is unlimited.

Overview

   This memo is a republication of RFC 1081 which was based on RFC 918
   (since revised as RFC 937).  Although similar in form to the original
   Post Office Protocol (POP) proposed for the Internet community, the
   protocol discussed in this memo is similar in spirit to the ideas
   investigated by the MZnet project at the University of California,
   Irvine.

   Further, 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.  The author gratefully acknowledges their
   interest.

Introduction

   On certain types of smaller nodes in the Internet it is often
   impractical to maintain a message transport system (MTS).  For
   example, a workstation may not have sufficient resources (cycles,
   disk space) in order to permit a SMTP server and associated local
   mail delivery system to be kept resident and continuously running.
   Similarly, it may be expensive (or impossible) to keep a personal
   computer interconnected to an IP-style network for long amounts of
   time (the node is lacking the resource known as "connectivity").

   Despite this, it is often very useful to be able to manage mail on
   these smaller nodes, and they often support a user agent (UA) to aid
   the tasks of mail handling.  To solve this problem, a node which can
   support an MTS entity offers a maildrop service to these less endowed
   nodes.  The Post Office Protocol - Version 3 (POP3) is intended to



Rose