SMTP Service Extension for 8-bit MIME Transport
RFC 6152
| Document | Type |
RFC - Internet Standard
(March 2011; No errata)
Obsoletes RFC 1652
Also known as STD 71
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 6152 (Internet Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Alexey Melnikov | ||
| Send notices to | (None) | ||
Internet Engineering Task Force (IETF) J. Klensin
Request for Comments: 6152
STD: 71 N. Freed
Obsoletes: 1652 Oracle
Category: Standards Track M. Rose
ISSN: 2070-1721 Dover Beach Consulting, Inc.
D. Crocker, Ed.
Brandenburg InternetWorking
March 2011
SMTP Service Extension for 8-bit MIME Transport
Abstract
This memo defines an extension to the SMTP service whereby an SMTP
content body consisting of text containing octets outside of the
US-ASCII octet range (hex 00-7F) may be relayed using SMTP.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6152.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Klensin, et al. Standards Track [Page 1]
RFC 6152 SMTP Extension for 8-bit MIME March 2011
1. Introduction
Although SMTP is widely and robustly deployed, various extensions
have been requested by parts of the Internet community. In
particular, a significant portion of the Internet community wishes to
exchange messages in which the content body consists of a MIME
message [RFC2045][RFC2046][RFC5322] containing arbitrary octet-
aligned material. This memo uses the mechanism described in the SMTP
specification [RFC5321] to define an extension to the SMTP service
whereby such contents may be exchanged. Note that this extension
does NOT eliminate the possibility of an SMTP server limiting line
length; servers are free to implement this extension but nevertheless
set a line length limit no lower than 1000 octets. Given that this
restriction still applies, this extension does NOT provide a means
for transferring unencoded binary via SMTP.
2. Framework for the 8-bit MIME Transport Extension
The 8-bit MIME transport extension is laid out as follows:
1. the name of the SMTP service extension defined here is
8bit-MIMEtransport;
2. the EHLO keyword value associated with the extension is 8BITMIME;
3. no parameter is used with the 8BITMIME EHLO keyword;
4. one optional parameter using the keyword BODY is added to the
MAIL command. The value associated with this parameter is a
keyword indicating whether a 7-bit message (in strict compliance
with [RFC5321]) or a MIME message (in strict compliance with
[RFC2046] and [RFC2045]) with arbitrary octet content is being
sent. The syntax of the value is as follows, using the ABNF
notation of [RFC5234]:
body-value = "7BIT" / "8BITMIME"
5. no additional SMTP verbs are defined by this extension; and
6. the next section specifies how support for the extension affects
the behavior of a server and client SMTP.
3. The 8bit-MIMEtransport Service Extension
When a client SMTP wishes to submit (using the MAIL command) a
content body consisting of a MIME message containing arbitrary lines
of octet-aligned material, it first issues the EHLO command to the
server SMTP. If the server SMTP responds with code 250 to the EHLO
Klensin, et al. Standards Track [Page 2]
RFC 6152 SMTP Extension for 8-bit MIME March 2011
command, and the response includes the EHLO keyword value 8BITMIME,
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