RFC 1870 (rfc1870) - Page 1 of 9


SMTP Service Extension for Message Size Declaration



Alternative Format: Original Text Document



Network Working Group                               J. Klensin, WG Chair
Request For Comments: 1870                                           MCI
STD: 10                                                 N. Freed, Editor
Obsoletes: 1653                             Innosoft International, Inc.
Category: Standards Track                                       K. Moore
                                                 University of Tennessee
                                                           November 1995


                         SMTP Service Extension
                      for Message Size Declaration

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

1.  Abstract

   This memo defines an extension to the SMTP service whereby an SMTP
   client and server may interact to give the server an opportunity to
   decline to accept a message (perhaps temporarily) based on the
   client's estimate of the message size.

2.  Introduction

   The MIME extensions to the Internet message protocol provide for the
   transmission of many kinds of data which were previously unsupported
   in Internet mail.  One expected result of the use of MIME is that
   SMTP will be expected to carry a much wider range of message sizes
   than was previously the case.  This has an impact on the amount of
   resources (e.g. disk space) required by a system acting as a server.

   This memo uses the mechanism defined in [5] to define extensions to
   the SMTP service whereby a client ("sender-SMTP") may declare the
   size of a particular message to a server ("receiver-SMTP"), after
   which the server may indicate to the client that it is or is not
   willing to accept the message based on the declared message size and
   whereby a server ("receiver-SMTP") may declare the maximum message
   size it is willing to accept to a client ("sender-SMTP").








Klensin, et al              Standards Track