Email Authentication Status Codes
draft-ietf-appsawg-email-auth-codes-00
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (appsawg WG) | |
|---|---|---|---|
| Author | Murray Kucherawy | ||
| Last updated | 2014-05-25 | ||
| Replaces | draft-kucherawy-email-auth-codes | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text htmlized pdfized bibtex | ||
| Reviews |
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| Stream | WG state | WG Document | |
| Document shepherd | S Moonesamy | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-appsawg-email-auth-codes-00
Network Working Group M. Kucherawy
Internet-Draft May 23, 2014
Intended status: Informational
Expires: November 24, 2014
Email Authentication Status Codes
draft-ietf-appsawg-email-auth-codes-00
Abstract
There is at present no way to return a status code to an email client
that indicates a message is being rejected or deferred specifically
because of email authentication failures. This document registers
codes for this purpose.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 24, 2014.
Copyright Notice
Copyright (c) 2014 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
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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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. New Status Codes . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. DKIM Failures Code . . . . . . . . . . . . . . . . . . . . 3
2.2. SPF Failures Code . . . . . . . . . . . . . . . . . . . . . 4
2.3. Reverse DNS Failure Code . . . . . . . . . . . . . . . . . 4
3. General Considerations . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
6. Normative References . . . . . . . . . . . . . . . . . . . . . 5
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 5
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1. Introduction
[RFC3463] introduced Enhanced Mail System Status Codes, and [RFC5248]
created an IANA registry for these.
[RFC6376] and [RFC7208] introduced, respectively, DomainKeys
Identified Mail and Sender Policy Framework, two protocols for
conducting email authentication. Another common email acceptance
test is the reverse Domain Name System check on an email client's IP
address, as described in Section 3 of [RFC7001].
The current set of enhanced status codes does not include any code
for indicating that a message is being rejected or deferred due to
local policy reasons related to either of these two mechanisms. This
document introduces enhanced status codes for reporting those cases
to clients.
2. New Status Codes
The following new status codes are defined:
2.1. DKIM Failures Code
Code: X.7.19
Sample Text: No valid DKIM signature found
Associated basic status code: 5
Description: This status code is returned when a message
did not contain a valid DKIM signature,
contrary to local policy requirements.
Reference: [this document]
Submitter: M. Kucherawy
Change controller: IESG
Code: X.7.20
Sample Text: No valid author DKIM signature found
Associated basic status code: 5
Description: This status code is returned when a message
did not contain a valid DKIM signature
matching the domain(s) found in the From
header field, contrary to local policy
requirements.
Reference: [this document]
Submitter: M. Kucherawy
Change controller: IESG
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2.2. SPF Failures Code
Code: X.7.21
Sample Text: SPF validation failed
Associated basic status code: 5
Description: This status code is returned when a message
failed an SPF check, contrary to local
policy requirements.
Reference: [this document]
Submitter: M. Kucherawy
Change controller: IESG
2.3. Reverse DNS Failure Code
Code: X.7.22
Sample Text: reverse DNS validation failed
Associated basic status code: 5
Description: This status code is returned when an SMTP
client's IP address failed a reverse DNS
validation check, contrary to local policy
requirements.
Reference: [this document]
Submitter: M. Kucherawy
Change controller: IESG
3. General Considerations
By the nature of the Simple Mail Transfer Protocol (SMTP), only one
enhanced status code can be returned for a given exchange between
client and server. However, an operator might decide to defer or
reject a message for a plurality of reasons. Clients receiving these
codes need to consider that the failure reflected by one of these
status codes might not reflect the only reason, or the most important
reason, for non-acceptance of the message or command.
4. Security Considerations
Use of these codes reveals local policy with respect to email
authentication, which can be useful information to actors attempting
to deliver undesirable mail. It should be noted that there is no
specific obligation to use these codes; if an operator wishes not to
reveal this aspect of local policy, it can continue using a generic
result code such as 5.7.7 or even 5.7.0.
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5. IANA Considerations
Registration of two new enhanced status codes, for addition to the
SMTP Enhanced Status Codes Registry, can be found in Section 2.
6. Normative References
[RFC3463] Vaudreuil, G., "Enhanced Mail System Status Codes",
RFC 3463, January 2003.
[RFC5248] Hansen, T. and J. Klensin, "A Registry for SMTP Enhanced
Mail System Status Codes", BCP 138, RFC 5248, June 2008.
[RFC6376] Crocker, D., Hansen, T., and M. Kucherawy, "DomainKeys
Identified Mail (DKIM) Signatures", STD 76, RFC 6376,
September 2011.
[RFC7001] Kucherawy, M., "Message Header Field for Indicating
Message Authentication Status", RFC 7001, September 2013.
[RFC7208] Kitterman, S., "Sender Policy Framework (SPF) for
Authorizing Use of Domains in Email, Version 1", RFC 7208,
April 2014.
Appendix A. Acknowledgments
Ned Freed, Arnt Gulbrandsen, and Barry Leiba contributed to this
work.
Author's Address
Murray S. Kucherawy
270 Upland Drive
San Francisco, CA 94127
USA
EMail: superuser@gmail.com
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