Update to Internet Message Format to Allow Group Syntax in the "From:" and "Sender:" Header Fields
RFC 6854
| Document | Type |
RFC - Proposed Standard
(March 2013; No errata)
Updates RFC 5322
Was draft-leiba-5322upd-from-group (individual in app area)
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 6854 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Pete Resnick | ||
| Send notices to | (None) | ||
Internet Engineering Task Force (IETF) B. Leiba
Request for Comments: 6854 Huawei Technologies
Updates: 5322 March 2013
Category: Standards Track
ISSN: 2070-1721
Update to Internet Message Format to Allow Group Syntax in
the "From:" and "Sender:" Header Fields
Abstract
The Internet Message Format (RFC 5322) allows "group" syntax in some
email header fields, such as "To:" and "CC:", but not in "From:" or
"Sender:". This document updates RFC 5322 to relax that restriction,
allowing group syntax in those latter fields, as well as in
"Resent-From:" and "Resent-Sender:", in certain situations.
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/rfc6854.
Copyright Notice
Copyright (c) 2013 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.
Leiba Standards Track [Page 1]
RFC 6854 Group Syntax in "From:" and "Sender:" March 2013
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 3
1.1.1. Requirements Notation . . . . . . . . . . . . . . . . . 3
1.1.2. Syntactic Notation . . . . . . . . . . . . . . . . . . 3
2. Allowing Group Syntax in "From:" and "Sender:" . . . . . . . . 3
2.1. Replacement of RFC 5322, Section 3.6.2. Originator Fields . 4
2.2. Update to RFC 5322, Section 3.6.6. Resent Fields . . . . . 5
3. Applicability Statement . . . . . . . . . . . . . . . . . . . . 6
4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.1. Normative References . . . . . . . . . . . . . . . . . . . 9
7.2. Informative References . . . . . . . . . . . . . . . . . . 9
1. Introduction
The Internet Message Format, as far back as RFC 822 [RFC0822], has
always required a usable address to appear in the "From:" header
field of messages in order to allow replies to be sent. To this end,
the syntax of messages, up to and including the current specification
[RFC5322], has required the use of the mailbox address form in the
originator ("From:" and "Sender:") fields of messages and has
specifically forbidden the use of the group address form, which
permits an empty list of addresses (that is, an address list with no
address included that might be used for a reply).
However, the use cases for the "From:" field have evolved. There are
numerous instances of automated systems that wish to send email but
cannot handle replies, and a "From:" field with no usable addresses
would be extremely useful for that purpose. More recently, work with
internationalized email addresses [RFC6530] creates a real need to
take a message with an internationalized email address and hand it to
an older client that would have no ability to reply to such an
address but might still wish to display the contents of the message.
The group construct provides an existing syntax for unusable
addresses (using the empty list of addresses) and also allows for a
text label that describes the originator. For example:
From: Automated System:;
A review of many current email programs finds that all reviewed
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