Implications of MIME for Internet Mail Gateways (RFC1344)
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2001-Nov-09
Publishing Venue
Internet Society Requests For Comment (RFCs)
Related People
Abstract
The recent development of MIME (Multipurpose Internet Mail Extensions) offers a wide range of new opportunities for electronic mail system systems. Most of these opportunites are relevant only to user agents, the programs that interact with human users when they send and receive mail. However, some opportunities are also opened up for mail transport systems. While MIME was carefully designed so that it does not require any changes to Internet electronic message transport facilities, there are several ways in which message transport systems may want to take advantage of MIME. These opportunities are the subject of this memo. (Download file contains alternative document formats.)
Network Working Group N. Borenstein, Bellcore
Request for Comments: 1344 June 1992
Implications of MIME for Internet Mail Gateways
Status of This Memo
This is an informational memo for the Internet community,
and requests discussion and suggestions for improvements.
This memo does not specify an Internet standard.
Distribution of this memo is unlimited.
Abstract
The recent development of MIME (Multipurpose Internet Mail
Extensions) offers a wide range of new opportunities for
electronic mail system systems. Most of these opportunites
are relevant only to user agents, the programs that interact
with human users when they send and receive mail. However,
some opportunities are also opened up for mail transport
systems. While MIME was carefully designed so that it does
not require any changes to Internet electronic message
transport facilities, there are several ways in which
message transport systems may want to take advantage of
MIME. These opportunities are the subject of this memo.
Background -- The MIME Format
Recently, a new standardized format has been defined for
enhanced electronic mail messages on the Internet. This
format, known as MIME, permits messages to include, in a
standardized manner, non-ASCII text, images, audio, and a
variety of other kinds of interesting data.
The MIME effort was explicitly focused on requiring
absolutely no changes at the message transport level.
Because of this fact, MIME-format mail runs transparently on
all known Internet or Internet-style mail systems. This
means that those concerned solely with the maintenance and
development of message transport services can safely ignore
MIME completely, if they so choose.
However, the fact that MIME can be ignored, for the purpose
of message transport, does not necessarily mean that it
should be ignored. In particular, MIME offers several
features that should be of interest to those responsible for
message transport services. By exploiting these features,
transport systems can provide certain additional kinds of
service that are currently unavailable, and can alleviate a
few existing problems.
The remainder of this document is an attempt to briefly
point out and summarize some important ways in which MIME
Borenstein [Page 1]
RFC 1344 MIME and Mail Gateways June 1992
may be of use for message transport systems. This document
makes no attempt to present a complete technical description
of MIME, however. For that, the reader is refered to the
MIME document itself [RFC-1341].
Mail Transport and Gateway Services: A Key Distinction
Before implementing any of the mechanisms discussed in this
memo, one should be familiar with the distinction between
mail transport service and mail gateway service. Basically,
mail transport software is responsible for moving a message
within a homogeneous electronic mail service network. Mail
gateways, on the other hand, exchange mail between two
significantly different mail environments, including via
non-electronic services, such as postal...