Update to Internet Message Format to Allow Group Syntax in the "From:" and "Sender:" Header Fields (RFC6854)
Original Publication Date: 2013-Mar-01
Included in the Prior Art Database: 2013-Mar-13
Internet Society Requests For Comment (RFCs)
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).
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
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 (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.
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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