Individual Submission                                  M. Kucherawy, Ed.
Internet-Draft                                                 Cloudmark
Obsoletes: 3462 (if approved)                           October 18, 2011
Intended status: Standards Track
Expires: April 20, 2012


    The Multipart/Report Media Type for the Reporting of Mail System
                        Administrative Messages
                    draft-ietf-appsawg-rfc3462bis-02

Abstract

   The multipart/report Multipurpose Internet Mail Extensions (MIME)
   media type is a general "family" or "container" type for electronic
   mail reports of any kind.  Although this memo defines only the use of
   the multipart/report media type with respect to delivery status
   reports, mail processing programs will benefit if a single media type
   is used for all kinds of reports.

   This memo obsoletes RFC3462.  The IESG is also requested to mark
   RFC1892 and RFC3462 as "historic".

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
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   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 April 20, 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
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of



Kucherawy                Expires April 20, 2012                 [Page 1]


Internet-Draft         Multipart/Report Media Type          October 2011


   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
   2.  Document Conventions . . . . . . . . . . . . . . . . . . . . .  4
   3.  The multipart/report Media Type  . . . . . . . . . . . . . . .  5
   4.  The text/rfc822-headers Media Type . . . . . . . . . . . . . .  8
   5.  Registering New Report Types . . . . . . . . . . . . . . . . . 10
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 13
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 13
   Appendix A.  Acknowledgements  . . . . . . . . . . . . . . . . . . 14
   Appendix B.  Document History  . . . . . . . . . . . . . . . . . . 15
   Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 17




























Kucherawy                Expires April 20, 2012                 [Page 2]


Internet-Draft         Multipart/Report Media Type          October 2011


1.  Introduction

   [OLD-REPORT] and its antecedent declared the multipart/report media
   type for use within the [MIME] construct to create a container for
   mail system administrative reports of various kinds.

   Practical experience has shown that the general requirement of having
   that media type constrained to be used only as the outermost MIME
   type of a message is overly and limits such things as the
   transmission of multiple administrative reports within a single
   overall message container.  In particular, it prevents one from
   forwarding a report as part of another multipart MIME message.

   This memo removes that constraint.  No other changes apart from some
   editorial ones are made.  Other memos might update other documents to
   establish or clarify the constraints on use of multipart/report in
   contexts where such are needed.

   This memo obsoletes RFC3462.  The IESG is also requested to mark
   RFC1892 and RFC3462 as "historic".































Kucherawy                Expires April 20, 2012                 [Page 3]


Internet-Draft         Multipart/Report Media Type          October 2011


2.  Document Conventions

   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].














































Kucherawy                Expires April 20, 2012                 [Page 4]


Internet-Draft         Multipart/Report Media Type          October 2011


3.  The multipart/report Media Type

   The multipart/report MIME media type is a general "family" or
   "container" type for electronic mail reports of any kind.  Although
   this memo defines only the use of the multipart/report media type
   with respect to delivery status reports, mail processing programs
   will benefit if a single media type is used for all kinds of reports.

   Per [MIME-REG], the multipart/report media type is defined as
   follows:

   Type name:  multipart

   Subtype name:  report

   Required parameters:  boundary, report-type

   Optional parameters:  none

   Encoding considerations:  7bit should always be adequate

   Security considerations:  see Section 7 of [this memo]

   Interoperability considerations:  see Section 1 of [this memo]

   Published specification:  [this memo]

   Applications that use this media type:  Mail Transfer Agents, Mail
      User Agents, spam detection and reporting modules, virus detection
      modules, message authentication modules

   Additional information:

      Magic number(s):  N/A

      File extensions(s):  N/A

      Macintosh file type code(s):  N/A

   Person and email address to contact for further information:  Murray
      S. Kucherawy <msk@cloudmark.com>

   Intended usage:  common

   Restrictions on usage:  none; however, other applications that
      register report types may establish such restrictions





Kucherawy                Expires April 20, 2012                 [Page 5]


Internet-Draft         Multipart/Report Media Type          October 2011


   Author:  Murray S. Kucherawy <msk@cloudmark.com>

   Change controller:  IESG

   The syntax of multipart/report is identical to the multipart/mixed
   content type defined in [MIME].  The report-type parameter identifies
   the type of report.  The parameter is the MIME sub-type of the second
   body part of the multipart/report.  (See Section 5.)

   The multipart/report media type contains either two or three sub-
   parts, in the following order:

   1.  (REQUIRED) The first body part contains a human readable message.
       The purpose of this message is to provide an easily understood
       description of the condition(s) that caused the report to be
       generated, for a human reader who might not have a user agent
       capable of interpreting the second section of the multipart/
       report.  The text in the first section can use any IANA-
       registered MIME media type, charset, or language.  Where a
       description of the error is desired in several languages or
       several media, a multipart/alternative construct MAY be used.
       This body part MAY also be used to send detailed information that
       cannot be easily formatted into the second body part.

   2.  (REQUIRED) A machine parsable body part containing an account of
       the reported message handling event.  The purpose of this body
       part is to provide a machine-readable description of the
       condition(s) that caused the report to be generated, along with
       details not present in the first body part that might be useful
       to human experts.  An initial body part, message/delivery-status
       is defined in [DSN-FORMAT].

   3.  (OPTIONAL) A body part containing the returned message or a
       portion thereof.  This information could be useful to aid human
       experts in diagnosing problems.  (Although it might also be
       useful to allow the sender to identify the message about which
       the report was issued, it is hoped that the envelope-id and
       original-recipient-address returned in the message/report body
       part will replace the traditional use of the returned content for
       this purpose.)

   Return of content can be wasteful of network bandwidth and a variety
   of implementation strategies can be used.  Generally the sender needs
   to choose the appropriate strategy and inform the recipient of the
   required level of returned content required.  In the absence of an
   explicit request for level of return of content such as that provided
   in [DSN-SMTP], the agent that generated the delivery service report
   SHOULD return the full message content.



Kucherawy                Expires April 20, 2012                 [Page 6]


Internet-Draft         Multipart/Report Media Type          October 2011


   When 8-bit or binary data not encoded in a 7-bit form is to be
   returned, and the return path is not guaranteed to be 8-bit or binary
   capable, two options are available.  The original message MAY be re-
   encoded into a legal 7-bit MIME message or the text/rfc822-headers
   media type MAY be used to return only the original message headers.














































Kucherawy                Expires April 20, 2012                 [Page 7]


Internet-Draft         Multipart/Report Media Type          October 2011


4.  The text/rfc822-headers Media Type

   The text/rfc822-headers media type provides a mechanism to label and
   return only the [MAIL] header of a failed message.  The header is not
   the complete message and SHOULD NOT be returned using the message/
   rfc822 media type defined in [MIME-TYPES].  The returned header is
   useful for identifying the failed message and for diagnostics based
   on the Received header fields.

   The text/rfc822-headers media type is defined as follows:

   Type name:  text

   Subtype name:  rfc822-headers

   Required parameters:  None

   Optional parameters:  None

   Encoding considerations:  7-bit is sufficient for normal mail
      headers, however, if the headers are broken or extended and
      require encoding to make them legal 7-bit content, they MAY be
      encoded with quoted-printable as defined in [MIME]

   Security considerations:  See Section 7 of [this memo].

   Interoperability considerations:  none

   Published specification:  [this memo]

   Applications that use this media type:  Mail Transfer Agents, Mail
      User Agents, spam detection and reporting modules, virus detection
      modules, message authentication modules

   Additional information:

      Magic number(s):  N/A

      File extensions(s):  N/A

      Macintosh file type code(s):  N/A

   Person and email address to contact for further information:  Murray
      S. Kucherawy <msk@cloudmark.com>







Kucherawy                Expires April 20, 2012                 [Page 8]


Internet-Draft         Multipart/Report Media Type          October 2011


   Intended usage:  common

   Restrictions on usage:  none

   Author:  Murray S. Kucherawy <msk@cloudmark.com>

   Change controller:  IESG

   The text/rfc822-headers body part SHOULD contain all the mail header
   fields from the message that caused the report.  The header includes
   all header fields prior to the first blank line in the message.  They
   include the MIME-Version and MIME content description fields.







































Kucherawy                Expires April 20, 2012                 [Page 9]


Internet-Draft         Multipart/Report Media Type          October 2011


5.  Registering New Report Types

   Registration of new media types for the purpose of creating a new
   report format SHOULD note in the Intended Usage section of the media
   type registration that the type being registered is suitable for use
   as a report-type (i.e., the second body part) in the context of this
   specification.












































Kucherawy                Expires April 20, 2012                [Page 10]


Internet-Draft         Multipart/Report Media Type          October 2011


6.  IANA Considerations

   IANA is directed to update the Media Type Registry to indicate that
   this memo contains the current definition of the multipart/report and
   text/rfc822-headers media types, obsoleting [OLD-REPORT].














































Kucherawy                Expires April 20, 2012                [Page 11]


Internet-Draft         Multipart/Report Media Type          October 2011


7.  Security Considerations

   Automated use of report types without authentication presents several
   security issues.  Forging negative reports presents the opportunity
   for denial-of-service attacks when the reports are used for automated
   maintenance of directories or mailing lists.  Forging positive
   reports can cause the sender to incorrectly believe a message was
   delivered when it was not.

   A signature covering the entire multipart/report structure could be
   used to prevent such forgeries; such a signature scheme is, however,
   beyond the scope of this document.







































Kucherawy                Expires April 20, 2012                [Page 12]


Internet-Draft         Multipart/Report Media Type          October 2011


8.  References

8.1.  Normative References

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

   [MAIL]     Resnick, P., "Internet Message Format", RFC 5322,
              October 2008.

   [MIME]     Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part One: Format of Internet Message
              Bodies", RFC 2045, November 1996.

   [MIME-REG]
              Freed, N. and J. Klensin, "Media Type Specifications and
              Registration Procedures", RFC 4288, December 2005.

   [MIME-TYPES]
              Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part Two: Media Types", RFC 2046,
              November 1996.

8.2.  Informative References

   [DSN-FORMAT]
              Moore, K. and G. Vaudreuil, "An Extensible Message Format
              for Delivery Status Notifications", RFC 3464,
              January 2003.

   [DSN-SMTP]
              Moore, K., "Simple Mail Transfer Protocol (SMTP) Service
              Extension for Delivery Status Notifications (DSNs)",
              RFC 3461, January 2003.

   [OLD-REPORT]
              Vaudreuil, G., "The Multipart/Report Content Type for the
              Reporting of Mail System Administrative Messages",
              RFC 3462, January 2003.











Kucherawy                Expires April 20, 2012                [Page 13]


Internet-Draft         Multipart/Report Media Type          October 2011


Appendix A.  Acknowledgements

   The author would like to thank Dave Crocker, Frank Ellermann, Ned
   Freed, Randall Gellens, Alexey Melnikov and Keith Moore for their
   input to this update.

   Thanks also go to Gregory M. Vaudreuil, the original creator of this
   media type.











































Kucherawy                Expires April 20, 2012                [Page 14]


Internet-Draft         Multipart/Report Media Type          October 2011


Appendix B.  Document History

   [RFC Editor: Please remove this section prior to publication.]

   Changes from draft-ietf-appsawg-rfc3462bis-01 to
   draft-ietf-appsawg-rfc3462bis-02:

   o  Minor copy editing based on WGLC feedback.

   o  Make OLD-REPORT into an informative reference.

   o  Update media type registration templates.

   Changes from draft-ietf-appsawg-rfc3462bis-00 to
   draft-ietf-appsawg-rfc3462bis-01:

   o  Minor copy editing based on WG feedback.

   Changes from draft-kucherawy-rfc3462bis-02 to
   draft-ietf-appsawg-rfc3462bis-00:

   o  Renamed.

   Changes from draft-kucherawy-rfc3462bis-01 to
   draft-kucherawy-rfc3462bis-02:

   o  Revert to removing the restriction altogether, noting that the DSN
      and MDN RFCs re-state it.  Thus, removing it here solves MARF's
      problem but doesn't impact DSN and MDN.  The restriction can be
      clarified on those documents in separate efforts.

   Changes from draft-kucherawy-rfc3462bis-00 to
   draft-kucherawy-rfc3462bis-01:

   o  Clarify requirement that multipart/report must be the outermost
      media type; require it only when generating a report.

   o  Highlight the forwarding-of-reports problem.

   o  Limit the constraint to time of report generation.

   o  Remove "Examples" section.

   Changes from RFC3462 to draft-kucherawy-rfc3462bis-00:

   o  Remove requirement that multipart/report not be contained in
      anything.




Kucherawy                Expires April 20, 2012                [Page 15]


Internet-Draft         Multipart/Report Media Type          October 2011


   o  Some minor adjustment to use current terminology, such as
      distinguishing between a header and a header field.

   o  More obvious use of the standard normative words.















































Kucherawy                Expires April 20, 2012                [Page 16]


Internet-Draft         Multipart/Report Media Type          October 2011


Author's Address

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

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









































Kucherawy                Expires April 20, 2012                [Page 17]