Individual submission                                         D. Crocker
Internet-Draft                               Brandenburg InternetWorking
Intended status: Standards Track                            M. Kucherawy
Expires: June 4, 2012                                    Cloudmark, Inc.
                                                        December 2, 2011


            Indicating Email Handling States in Trace Fields
                   draft-kucherawy-received-state-01

Abstract

   This memo registers a trace field clause for use in indicating
   transitions between handling queues, including enacting inter-host
   message transitions.  This might include message quarantining,
   mailing list moderation, timed delivery, or other similar causes.

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
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   This Internet-Draft will expire on June 4, 2012.

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
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   described in the Simplified BSD License.



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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Keywords  . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  New Trace Clause  . . . . . . . . . . . . . . . . . . . . . . . 3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
     4.1.  Mail Parameters Additional-registered-clauses
           Sub-Registry  . . . . . . . . . . . . . . . . . . . . . . . 4
     4.2.  Mail Parameters Registered-states Sub-Registry  . . . . . . 5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . . . 5
   6.  Normative References  . . . . . . . . . . . . . . . . . . . . . 6
   Appendix A.  Trace Field Examples . . . . . . . . . . . . . . . . . 6
     A.1.  Typical Delivery Without Obvious Delays . . . . . . . . . . 6
     A.2.  Delivery With Moderation  . . . . . . . . . . . . . . . . . 7
   Appendix B.  Acknowledgements . . . . . . . . . . . . . . . . . . . 7




































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1.  Introduction

   [SMTP] defines the content of email message trace fields, commonly
   the "Received" field.  These are typically used to record an audit
   trail of the path a message follows from origin to destination.

   There are some cases where there may be large time gaps between trace
   fields.  Though this might be caused by transient delivery issues,
   they might also be caused by policy decisions or special processing
   regarding the content of the message or authorization of some
   identity on the message.  Common examples include message quarantines
   (filters that delay relaying or delivery of a message pending manual
   operator action), or mailing list moderation rules (mailing list
   owner action required regarding mail from authors not subscribed to
   those lists).

   This memo registers a new optional clause that can be used in trace
   fields to indicate that a message entered such a special processing
   queue for some period.  This allows analysis to reveal that the cause
   for a time gap in trace fields was an imposed delay rather than one
   caused by transient technical difficulties.

2.  Keywords

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [KEYWORDS].

3.  New Trace Clause

   This memo creates a new trace field clause, called "state", which can
   be used to indicate the nature of a delay imposed on relaying of a
   message toward its recipient(s).  It is followed by a single keyword
   that provides that detail.  An MTA or other handling agent that
   determines a message is about to enter a state other than normal
   queueing of messages for delivery SHOULD generate a trace field
   including one of these clauses.  That is, the presence of this clause
   on a trace field is an indication of the entry of the message into
   that state; a later trace field added would indicate its departure
   from that state.

   The following keywords are defined in this document; extensions may
   define other registered keywords (see Section 4.2):

   moderation:  The message entered a hold pending mailing list
      moderator action.





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   other:  The message entered a hold for reasons not covered by other
      keywords in this list, and not for transient technology issues.

   timed:  The message entered a hold in order to meet a requested
      delivery window.

   quarantine:  The message entered a hold pending operator action for
      local policy reasons.

   The ABNF for this clause:

      State = "state" queue-state-keyword

      queue-state-keyword = ( reg-state-keyword / unreg-state-keyword )

      reg-state-keyword = ( "moderation" / "other" /
                            "quarantine" / "timed" /
                            additional-state-keyword )

      additional-state-keyword = unstructured
                               ; see "IANA Considerations" below

      unreg-state-keyword = unstructured
                          ; from [MAIL]

   A transfer agent making use of this extension MAY also include header
   field comments to provide additional information.

   Use of this clause by transfer agents is OPTIONAL.

4.  IANA Considerations

4.1.  Mail Parameters Additional-registered-clauses Sub-Registry

   This memo adds to the "Additional-registered-clauses" sub-registry of
   the "Mail Parameters" registry, created by [SMTP], the following
   entry:

   Clause name:  state

   Description:  Indicates special queue state entry

   State Summary:  state <state-name>

   Reference:  [this memo]






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4.2.  Mail Parameters Registered-states Sub-Registry

   The "Mail Parameters" registry at IANA is updated by the creation of
   the "Registered-states" sub-registry to contain valid state keywords
   for use with this specification.  Updates to this registry are
   governed by the Specification Required rules of [IANA].
   Registrations must include the following entries:

   Name:  The name of the state keyword being defined or updated

   Description:  A brief description of the keyword's meaning

   Specification:  The specification document that defines the queue
      state being registered

   Use:  One of "current" (the state keyword is in current use),
      "deprecated" (the state keyword is in use but not recommended for
      new implementations), or "historic" (the state keyword is no
      longer in substantial current use).

   The initial registration set is as follows:

    +------------+---------------------------+---------------+---------+
    | Name       | Description               | Specification | Use     |
    +------------+---------------------------+---------------+---------+
    | moderation | Held for list moderation  |  [this memo]  | current |
    +------------+---------------------------+---------------+---------+
    | other      | Held for causes not       |  [this memo]  | current |
    |            | covered by other          |               |         |
    |            | registered state keywords |               |         |
    +------------+---------------------------+---------------+---------+
    | quarantine | Held for operator action  |  [this memo]  | current |
    |            | due to content analysis   |               |         |
    |            | or local policy           |               |         |
    +------------+---------------------------+---------------+---------+
    | timed      | Held to accommodate a     |  [this memo]  | current |
    |            | specific requested        |               |         |
    |            | delivery window           |               |         |
    +------------+---------------------------+---------------+---------+

5.  Security Considerations

   The use of this trace information can reveal hints as to local policy
   that was in effect at the time of message handling.







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6.  Normative References

   [IANA]      Narten, T. and H. Alvestrand, "Guidelines for Writing an
               IANA Considerations Section in RFCs", BCP 26, RFC 5226,
               May 2008.

   [KEYWORDS]  Bradner, S., "Key words for use in RFCs to Indicate
               Requirement Levels", BCP 14, RFC 2119, March 1997.

   [SMTP]      Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
               October 2008.

Appendix A.  Trace Field Examples

   This section includes a sample of the new trace field clause in use.

A.1.  Typical Delivery Without Obvious Delays

   Typical message delivery

        Received: from newyork.example.com
                  (newyork.example.com [192.0.2.250])
              by mail-router.example.net (8.11.6/8.11.6)
                  with ESMTP id i7PK0sH7021929
                  for <recipient@example.net>;
              Fri, Feb 15 2002 17:19:22 -0800
        Received: from internal.example.com
                  (internal.example.com [192.168.0.1])
              by newyork.example.com (8.11.6/8.11.6)
                  with ESMTP id i9MKZCRd064134
                  for <recipient@example.net>;
              Fri, Feb 15 2002 17:19:08 -0800

   Example 1: Typical message delivery with no appreciable handling
   delays; only Received fields shown
















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A.2.  Delivery With Moderation

   Message delivery after moderation

        Received: from newyork.example.com
                  (newyork.example.com [192.0.2.250])
              by mail-router.example.net (8.11.6/8.11.6)
                  with ESMTP id i7PK0sH7021929
                  for <recipient@example.net>;
              Fri, Feb 15 2002 18:33:29 -0800
        Received: from internal.example.com
                  (internal.example.com [192.168.0.1])
              by newyork.example.com (8.11.6/8.11.6)
                  with ESMTP id i9MKZCRd064134
                  for <secret-list@example.com&gt
                  state moderation (sender not subscribed);
              Fri, Feb 15 2002 17:19:08 -0800

   Example 2: Message held for moderation; only Received fields shown

   The message passed from internal.example.com to newyork.example.com
   intended for a mailing list hosted at the latter.  For list
   administrative reasons, the message is held there for moderation.  It
   is finally released over an hour later and passed to the next host.
   A comment after the state expression indicates the actual cause for
   the administrative hold.

Appendix B.  Acknowledgements

   The author wishes to acknowledge the following for their review and
   constructive criticism of this proposal: Tony Finch, and Bill
   McQuillan.

Authors' Addresses

   D. Crocker
   Brandenburg InternetWorking
   675 Spruce Dr.
   Sunnyvale  94086
   USA

   Phone: +1.408.246.8253
   EMail: dcrocker@bbiw.net
   URI:   http://bbiw.net







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   Murray S. Kucherawy
   Cloudmark, Inc.
   128 King St., 2nd Floor
   San Francisco, CA  94107
   US

   Phone: +1 415 946 3800
   EMail: msk@cloudmark.com











































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