Interoperability Issues between Domain-based Message Authentication, Reporting, and Conformance (DMARC) and Indirect Email Flows
RFC 7960
Internet Engineering Task Force (IETF) F. Martin, Ed.
Request for Comments: 7960 LinkedIn
Category: Informational E. Lear, Ed.
ISSN: 2070-1721 Cisco Systems GmbH
T. Draegen, Ed.
dmarcian, inc.
E. Zwicky, Ed.
Yahoo
K. Andersen, Ed.
LinkedIn
September 2016
Interoperability Issues between Domain-based Message Authentication,
Reporting, and Conformance (DMARC) and Indirect Email Flows
Abstract
Domain-based Message Authentication, Reporting, and Conformance
(DMARC) introduces a mechanism for expressing domain-level policies
and preferences for email message validation, disposition, and
reporting. However, the DMARC mechanism enables potentially
disruptive interoperability issues when messages do not flow directly
from the author's administrative domain to the final Recipients.
Collectively, these email flows are referred to as "indirect email
flows". This document describes these interoperability issues and
presents possible methods for addressing them.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
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). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 7841.
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/rfc7960.
Martin, et al. Informational [Page 1]
RFC 7960 DMARC Indirect Email Interop Issues September 2016
Copyright Notice
Copyright (c) 2016 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.
Table of Contents
1. Introduction ....................................................3
1.1. Document Conventions .......................................4
2. Causes of Interoperability Issues ...............................4
2.1. Identifier Alignment .......................................4
2.1.1. DKIM Identifier(s) ..................................5
2.1.2. SPF Identifier(s) ...................................6
2.1.3. Multiple RFC5322.From Addresses .....................6
2.2. Message Forwarding .........................................6
2.3. Message Modification .......................................7
3. Internet Mail Architecture, DMARC, and Indirect Email Flows .....8
3.1. Message Handling System ....................................8
3.1.1. Message Submission Agents ...........................8
3.1.2. Message Transfer Agents .............................9
3.1.2.1. Message Encoding ...........................9
3.1.2.2. Header Standardization ....................10
3.1.2.3. Content Validation ........................10
3.1.3. Message Delivery Agents ............................10
3.2. Mediators .................................................11
3.2.1. Alias ..............................................11
3.2.2. ReSenders ..........................................12
3.2.3. Mailing Lists ......................................12
3.2.3.1. Mailing List Operational Effects ..........13
3.2.4. Gateways ...........................................13
3.2.5. Boundary Filters ...................................14
3.3. Combinations ..............................................15
4. Possible Mitigations of Interoperability Issues ................15
Show full document text