Network Working Group                                         R. Gellens
Request for Comments: 4356                                      Qualcomm
Category: Standards Track                                   January 2006


        Mapping Between the Multimedia Messaging Service (MMS)
                          and Internet Mail

Status of This Memo

  This document specifies an Internet standards track protocol for the
  Internet community, and requests discussion and suggestions for
  improvements.  Please refer to the current edition of the "Internet
  Official Protocol Standards" (STD 1) for the standardization state
  and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

  Copyright (C) The Internet Society (2006).

Abstract

  The cellular telephone industry has defined a service known as the
  Multimedia Messaging Service (MMS).  This service uses formats and
  protocols that are similar to, but differ in key ways from, those
  used in Internet mail.

  One important difference between MMS and Internet Mail is that MMS
  uses headers that start with "X-Mms-" to carry a variety of user
  agent- and server-related information elements.

  This document specifies how to exchange messages between these two
  services, including mapping information elements as used in MMS
  X-Mms-* headers as well as delivery and disposition reports, to and
  from that used in SMTP and Internet message headers.
















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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


Table of Contents

  1. Introduction ....................................................2
     1.1. Scope ......................................................2
     1.2. Conventions Used in This Document ..........................3
     1.3. Definitions ................................................3
     1.4. Abbreviations ..............................................4
     1.5. Assumptions ................................................4
  2. Mapping Between MMS and Internet Mail ...........................4
     2.1. Mapping Specification ......................................5
          2.1.1. MMS to Internet Mail ................................5
          2.1.2. Internet Mail to MMS ................................5
          2.1.3. MMS Information Element Mappings ....................6
          2.1.4. Report Generation and Conversion ...................20
          2.1.5. Message Delivery ...................................27
  3. Security Considerations ........................................27
  4. IANA Considerations ............................................27
  5. Acknowledgements ...............................................27
  6. Normative References ...........................................27
  7. Informative References .........................................29

1.  Introduction

1.1.  Scope

  This document describes how to exchange messages between Multimedia
  Messaging Service (MMS) systems (as defined by [3GPP][3GPP2][OMA])
  and Internet mail systems (that is, [SMTP] and [Msg-Fmt]).  This
  includes the translation of message formats, message header elements,
  message delivery reports [DSN-Msg], and message disposition reports
  [MDN].

  The MMS architecture [Stage_2] and specifications [Stage_3] refer to
  interfaces as reference points named MMx.  For example, MM1 is the
  client-server interface, MM4 is the server-server interface, and MM3
  is an interface to "external" or non-MMS systems.  The specification
  in this document can be used for message exchange between any system
  that uses Internet message formats and protocols and an MMS system;
  from the perspective of the MMS system, reference point MM3 is used.

  This document includes support for voice messages specified by the
  Voice Profile for Internet Mail [VPIM].  The VPIM specification
  allows voice messages to be exchanged between voice mail systems
  using the Internet mail format [Msg-Fmt] and transported via [SMTP].
  Thus, the MMS MM3 interface supports the ability to exchange voice
  messages between an MMS system and a voice mail system.  Note that
  such use is distinct from voice media being part of a user-composed
  multimedia message.



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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Note that MM3 can also be used for interworking with "external"
  (non-MMS) systems other than Internet mail, such as Short Messaging
  Service (SMS) and access to external mail stores (such as a voice
  mail system).  This specification does not address these other uses
  or sub-interfaces of MM3; it is only concerned with Internet mail
  interworking and specifically exchange of messages.

  All MM3 Stage 2 [Stage_2] functions are supported except for reply
  charging and sender address hiding.

1.2.  Conventions Used in This Document

  The key words "REQUIRED", "MUST", "MUST NOT", "SHOULD", "SHOULD NOT",
  and "MAY" in this document are to be interpreted as described in "Key
  Words for Use in RFCs to Indicate Requirement Levels" [KEYWORDS].

1.3.  Definitions

  --------------------|----------------------------------------------
  Body                |The portion of an [SMTP] message's Content
                      |following the Header (that is, following the
                      |first blank line).  The Body may contain
                      |structured parts and sub-parts, each of which
                      |may have its own Header and Body.  The Body
                      |contains information intended for the message
                      |recipient (human or software).
  --------------------|----------------------------------------------
  Content             |The portion of an SMTP message that is
                      |delivered.  The Content consists of a Header
                      |and a Body.
  --------------------|----------------------------------------------
  Disposition Report  |Feedback information to an originator User
                      |Agent by a recipient User Agent about
  Message Disposition |handling of an original message.  This may
     Notification     |include notification that the message was or
                      |was not read, was deleted unread, etc.
  --------------------|----------------------------------------------
  Envelope            |The portion of an SMTP message not included in
                      |the Content, that is, not in the Header or in
                      |the Body.  While some of it may be copied into
                      |the Content on delivery, envelope information
                      |exists only while the message is in transit,
                      |and contains information used by SMTP agents
                      |(Mail Transfer Agents (MTAs)).
  --------------------|----------------------------------------------
  Gateway             |See [SMTP], Section 2.3.8.
  --------------------|----------------------------------------------




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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  --------------------|----------------------------------------------
  Header              |The first part of an SMTP message's Content.
                      |The Header is separated from the Body by a
                      |blank line.  The Header consists of Fields
                      |(such as "To:"), also known as Header Fields
                      |or Headers.  The message Header contains
                      |information used by User Agents.
  --------------------|----------------------------------------------
  Relay/Server        |An MMS server.  See [Stage_2].  For purposes
                      |of this document, an MMS Relay/Server acts as
                      |a gateway when it receives or sends messages
                      |via Internet mail.
  --------------------|----------------------------------------------
  User Agent          |An MMS or email user agent.
  --------------------|----------------------------------------------

1.4.  Abbreviations

  --------|----------------------------------------------------------
  MSA     |Message Submission Agent.  A server that accepts messages
          |from User Agents and processes them, either delivering
          |them locally or relaying to an MTA.  See [Submission].
  --------|----------------------------------------------------------
  MTA     |Mail Transfer Agent.  A server that implements [SMTP].
  --------|----------------------------------------------------------

1.5.  Assumptions

  It is assumed that the reader is already familiar with the contents
  of the 3GPP2 MMS Specification Overview [Overview], MMS Stage 1
  (requirements) [Stage_1] and Stage 2 (architecture and abstract
  messages) [Stage_2], and 3GPP/3GPP2 Stage 3 (protocols) [Stage_3]
  documents.  It is also assumed that the reader is familiar with
  Internet mail, especially RFC 2821 [SMTP] and RFC 2822 [Msg-Fmt].

2.  Mapping Between MMS and Internet Mail

  This section defines the interworking between MMS Relay/Servers and
  External Servers using native [SMTP].  That is, information elements
  are exchanged using standard Internet message [Msg-Fmt] header
  fields, such as those in [Hdrs], and standard [SMTP] elements.

  SMTP and Internet mail extensions are used for features such as
  delivery reports, message expiration, and discovery of server support
  for optional features.






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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


2.1.  Mapping Specification

2.1.1.  MMS to Internet Mail

  When sending a message to an Internet mail system, the MMS
  Relay/Server MUST convert the MM if required, and MUST comply with
  the requirements of [SMTP].

  The MMS Relay/Server SHOULD use the information elements associated
  with the MM to define the control information (Internet message
  header fields and SMTP envelope values) needed for the transfer
  protocol.

  Section 2.1.3 lists the mappings between X-Mms-* headers and Internet
  message header fields and SMTP values.

  Delivery and read report MMs SHOULD be converted to standard Internet
  message report format (multipart/report).  In addition to converting
  Internet Message reports, the MMS Relay/Server MUST generate delivery
  and read report MMs for received messages as appropriate.  See
  Section 2.1.4 for more information.

2.1.2.  Internet Mail to MMS

  When receiving a message from an Internet mail system, the MMS
  Relay/Server converts incoming messages to the MM format used within
  the receiving system.

  The MMS Relay/Server converts control information received from the
  Internet mail server into appropriate information elements of an MM.

  Section 2.1.3 lists the mappings between X-Mms-* headers and Internet
  message header fields and SMTP values.

  Standard Internet message report format (multipart/report) messages
  MAY be converted to delivery or read report MMs, as appropriate.  In
  addition to converting report MMs, implementations conforming to this
  document MUST generate standard Internet message delivery and
  disposition reports for received Internet messages as appropriate.
  See Section 2.1.4 for more information.











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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


2.1.3.  MMS Information Element Mappings

  The mappings between MMS elements and SMTP/Internet message elements
  ([SMTP] parameters, [Msg-Fmt] headers, and [DSN-Msg] fields) are
  summarized in table 1 below, and detailed in subsequent sections.
  The "MMS Headers" are from [OMA-MMS].  Note that only information
  elements that need to be mapped are listed. [Msg-Fmt] headers not
  listed here SHOULD be passed unaltered.

2.1.3.1.  Table 1:  Information Element Mappings

  =================|=================|================|==============
  Information Elem |[SMTP] Element   |[Msg-Fmt] Header|MMS Header
  =================|=================|================|==============
  3GPP MMS Version |N/A              |N/A             |X-Mms-3GPP-MMS
                   |                 |                |   -Version:
  _________________|_________________|________________|______________
  Message Type     |N/A              |N/A             |X-Mms-Message-
  (of PDU)         |                 |                |   Type:
  _________________|_________________|________________|______________
  Transaction ID   |N/A              |N/A             |X-Mms-Transact
                   |                 |                |   ion-Id:
  _________________|_________________|________________|______________
  Message ID       |N/A              |Message-ID:     |Message-ID:
  _________________|_________________|________________|______________
  Recipient        |RCPT TO          |To:, Cc:, or    |To:, Cc:, Bcc:
  address(es)      |address(es)      |omitted (Bcc)   |
  _________________|_________________|________________|______________
  Sender's address |MAIL FROM        |From:           |From:
                   |address if       |                |
                   |user-originated; |                |
                   |MUST set MAIL    |                |
                   |FROM to null     |                |
                   |("<>") for all   |                |
                   |automatically-   |                |
                   |generated MMs    |                |
  _________________|_________________|________________|______________
  Content type     |N/A              |Content-Type:   |Content-type:
                   |                 |                |
                   |                 |For voice mes-  |
                   |                 |sages compliant |
                   |                 |to [VPIM], see  |
                   |                 |Note 2          |
  _________________|_________________|________________|______________







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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  =================|=================|================|==============
  Information Elem |[SMTP] Element   |[Msg-Fmt] Header|MMS Header
  =================|=================|================|==============
  Message class    |Class=auto:      |MAY set 'Prece  |X-Mms-Message-
                   |MUST set MAIL    |   dence: bulk' |   Class:
                   |FROM to null     |on class=auto   |
                   |("<>").          |                |
  _________________|_________________|________________|______________
  Date and time    |N/A              |Date:           |Date:
  of submission    |                 |                |
  _________________|_________________|________________|______________
  Time of expiry   |DELIVER-BY       |N/A             |X-Mms-Expiry:
                   |[Deliver-By]     |                |
  _________________|_________________|________________|______________
  Earliest deliv-  |(only for submis-|N/A             |X-Mms-Delivery
  ery time         |sion; not relay) |                |   -Time:
  _________________|_________________|________________|______________
  Delivery report  |DSN [DSN-SMTP]   |N/A             |X-Mms-Delivery
  request          |SHOULD also      |                |   -Report:
                   |specify recip-   |                |
                   |ient address as  |                |
                   |ORCPT; SHOULD    |                |
                   |also specify     |                |
                   |ENVID            |                |
  _________________|_________________|________________|______________
  Importance (a/k/a|N/A              |Importance:     |X-Mms-
  "priority")      |                 |                |   Priority:
                   |                 |                |
                   |                 |                |
  _________________|_________________|________________|______________
  Sender visib-    |(not currently   |(not currently  |X-Mms-Sender-
  ility            |supported)       |supported)      |   Visibility:
  _________________|_________________|________________|______________
  Read reply       |N/A              |Disposition-    |X-Mms-Read-
  request          |                 |   Notification |   Reply:
                   |                 |   -To: [MDN]   |
  _________________|_________________|________________|______________
  Reply-charging   |(not currently   |(not currently  |X-Mms-Reply-
  permission       |supported)       |supported)      |   Charging:
  _________________|_________________|________________|______________
  Reply-charging   |(not currently   |(not currently  |X-Mms-Reply-
  permission       |supported)       |supported)      |   Charging-
  deadline         |                 |                |   Deadline:
  _________________|_________________|________________|______________
  Reply-charging   |(not currently   |(not currently  |X-Mms-Reply-
  permission       |supported)       |supported)      |   Charging-
  limitation       |                 |                |   Size:
  _________________|_________________|________________|______________



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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  =================|=================|================|==============
  Information Elem |[SMTP] Element   |[Msg-Fmt] Header|MMS Header
  =================|=================|================|==============
  Reply charging   |(not currently   |(not currently  |X-Mms-Reply-
  usage request    |supported)       |supported)      |   Charging-
                   |                 |                |   Id:
  _________________|_________________|________________|______________
  Reply charging   |(not currently   |(not currently  |X-Mms-Reply-
  usage reference  |supported)       |supported)      |   Charging:
  _________________|_________________|________________|______________
  Subject          |N/A              |Subject:        |Subject:
  _________________|_________________|________________|______________
  Previously-sent  |N/A              |Resent-From:    |X-Mms-Previous
  by               |                 |                |   ly-Sent-By:
  _________________|_________________|________________|______________
  Previously-sent  |N/A              |Resent-Date:    |X-Mms-
  date             |                 |                |   Previously-
                   |                 |                |   Sent-Date-
                   |                 |                |   and-Time:
  _________________|_________________|________________|______________
  Hop/host trace   |N/A              |Received:       |(Not sup-
                   |                 |                |ported)
  _________________|_________________|________________|______________
  Sensitivity      |N/A              |Sensitivity: see|N/A
                   |                 |Note 1          |
  _________________|_________________|________________|______________
  Content          |N/A              |<message body>  |<message body>
  =================|=================|================|==============

  Note 1:  The [VPIM] 'Sensitivity' header element indicates the
  privacy requested by the message originator (values are "personal" or
  "private"); per [VPIM], a message recipient MUST NOT forward a
  message with a 'Sensitivity' header.  Since sensitivity is not an MMS
  feature, any messages that contain a 'Sensitivity:' header SHOULD NOT
  be sent to an MMS system.

  Note 2: [VPIM] specifies how conforming messages are identified.

2.1.3.2.  Conversion of Messages from MMS to Internet Format

  3GPP MMS Version

  The 'X-Mms-3GPP-MMS-Version:' header, if present, SHOULD be removed.

  Message Type (of PDU)

  The 'X-Mms-Message-Type:' header, if present, SHOULD be removed.




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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Transaction ID

  The 'X-Mms-Transaction-Id:' header, if present, SHOULD be removed.

  Message ID

  The 'Message-Id:' header MUST be retained.  If not present, it MUST
  be created, with a unique value, per [Msg-Fmt].

  To facilitate the case where an MMS message traverses the Internet
  prior to returning to an MMS system, implementations might wish to
  retain the 'X-Mms-Message-Id:' header.  Such systems should be aware
  that headers that begin with "X-" might be removed during transit
  through Internet MTAs.

  Recipient(s) address

  The address of each recipient MUST be transmitted in the [SMTP]
  envelope as a RCPT TO value.  All disclosed recipients SHOULD also
  appear in a 'To:' or 'Cc:' header.  At least one 'To:', 'Cc:', or
  'Bcc:' header MUST be present.  If none are present, a 'To:' header
  SHOULD be created using empty group syntax whose name gives an
  indication to a human reader, for example, 'To:  undisclosed-
  recipients:;'.

  The 'To:' header SHOULD NOT appear more than once.  The 'Cc:' header
  SHOULD NOT appear more than once.

  Each recipient address MUST obey the length restrictions per [SMTP].

  Current Internet Message format requires that only 7-bit US-ASCII
  characters be present in headers.  Non-7-bit characters in an address
  domain must be encoded with [IDN].  If there are any non-7-bit
  characters in the local part of an address, the message MUST be
  rejected.  Non-7-bit characters elsewhere in a header MUST be encoded
  according to [Hdr-Enc].

  All recipient addresses in the [SMTP] envelope must be fully-
  qualified in accordance with [SMTP].  In particular, messages MUST
  NOT be sent to an Internet mail system with an unqualified E.164
  number (i.e., a number with no domain) instead of a fully-qualified
  domain name.

  All addresses in 'To:', 'Cc:', and 'Bcc:' headers MUST be in the form
  of fully-qualified domains.  Unqualified E.164 numbers MUST NOT be
  used.





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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Sender address

  The address of the message sender SHOULD appear in the 'From:'
  header.

  The address of the message sender for all user-generated messages
  ('X-Mms-Message-Class:  Personal') SHOULD be transmitted in the
  [SMTP] envelope as the MAIL FROM value.

  The return addresses in the [SMTP] envelope must be fully-qualified
  in accordance with [SMTP].  In particular, messages MUST NOT be sent
  to an Internet mail system with an E.164 number instead of a fully-
  qualified domain name.  Note that qualified E.164 numbers, that is,
  those that contain an E.164 number as the local-part of an address
  that also includes a domain, are acceptable.

  The address(es) in the 'From:' header SHOULD be in the form of
  fully-qualified domains.  Unqualified E.164 numbers SHOULD NOT be
  used.

  Because of the risk of mail loops, it is critical that the MAIL FROM
  be set to null ("<>") for all automatically-generated MMs (such as
  'X-Mms-Message-Class:  Auto').  The MAIL FROM value MUST be set to
  null for all automatically-generated messages.  This includes
  reports, "out-of-office" replies, etc.

  Current Internet message format requires that only 7-bit US-ASCII
  characters be present in headers.  Non-7-bit characters in an address
  domain must be encoded with [IDN].  If there are any Non-7-bit
  characters in the local part of an address, the message MUST be
  rejected.  Non-7-bit characters elsewhere in a header MUST be encoded
  according to [Hdr-Enc].  Note that it would be possible to define an
  [SMTP] extension to permit transmission of unencoded 8-bit
  characters, but in the absence of such an extension [Hdr-Enc] MUST be
  used.

  The sender address MUST obey the length restrictions of [SMTP].

  Content type

  The 'Content-Type:' header SHOULD be preserved.










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RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Message class

  The 'X-Mms-Message-Class:' header MAY be retained in order to provide
  information on the source of the message.  A 'Precedence:  bulk'
  header MAY be inserted for class=auto or class=advertisement.  See
  'Sender Address' above. (Class=personal and class=informational do
  not require special handling.)

  Time of Expiry

  The 'X-Mms-Expiry:' header, if present, SHOULD be removed.

  The remaining time until the message is considered expired SHOULD be
  transmitted in the [SMTP] envelope by using the DELIVER-BY extension
  with a by-mode of "R", as specified in [Deliver-By].

  Note that the [SMTP] DELIVER-BY extension carries time remaining
  until expiration; each server decrements the value by the amount of
  time it has possessed the message.  The 'X-Mms-Expiry:' header may
  contain either the absolute time at which the message is considered
  expired or the relative time until the message is considered expired.

  Earliest delivery time

  The 'X-Mms-Delivery-Time:' header, if present, SHOULD be removed.

  Future delivery is a message submission (e.g., [Submission]), not
  message relay feature.

  Delivery report request

  Requests for delivery status notifications (DSNs) SHOULD be
  transmitted in the [SMTP] envelope by using the DSN extension as
  specified in [DSN-SMTP] to request "success" or "none" notification
  (depending on the value of the 'X-Mms-Delivery-Report' header).  When
  the NOTIFY extension is used, the unaltered recipient address SHOULD
  be transmitted as the ORCPT value.

  The 'X-Mms-Delivery-Report:' header, if present, SHOULD be removed.

  Importance

  The message sender's importance value (also called "priority",
  although this can be confused with class-of-service values) SHOULD be
  transmitted using an 'Importance:' header.

  Suggested mappings are shown in Table 2:




Gellens                     Standards Track                    [Page 11]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


2.1.3.2.1.  Table 2:  Importance Mappings (MMS to Internet Message)

     ---------------------------|------------------
     'X-Mms-Priority: High'     |'Importance: High'
     ---------------------------|------------------
     'X-Mms-Priority: Normal'   |[omit]
     ---------------------------|------------------
     'X-Mms-Priority: Low'      |'Importance: Low'
     ---------------------------|------------------

  Normal importance messages should omit the 'Importance:' header.

  The 'X-Mms-Priority:' header, if present, SHOULD be removed.

  Sender visibility

  Support for sender address hiding is not currently supported.

  A message that contains an 'X-Mms-Sender-Visibility:' header with a
  value of 'Hide' SHOULD be rejected.

  The 'X-Mms-Sender-Visibility:' header, if present, SHOULD be removed.

  Read reply request

  A request for a read reply SHOULD be transmitted using a
  'Disposition-Notification-To:' header as specified in [MDN].

  The 'X-Mms-Read-Reply:' header, if present, SHOULD be removed.

  Reply charging

  Reply charging permission and acceptance are complex issues requiring
  both user agent and server support.  Misapplied reply charging may
  cause incorrect billing.  Until the security issues have been
  properly addressed, reply charging SHOULD NOT be honored when using
  this interface.

  The 'X-Mms-Reply-Charging:', 'X-Mms-Reply-Charging-Deadline:', 'X-
  Mms-Reply-Charging-Size:', and 'X-Mms-Reply-Charging-Id:' headers MAY
  be removed.  Messages containing a reply-charging usage request ('X-
  Mms-Reply-Charging-Id:' and 'X-Mms-Reply-Charging: accepted' or 'X-
  Mms-Reply-Charging: accepted (text only)' headers) SHOULD be
  rejected.







Gellens                     Standards Track                    [Page 12]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Subject

  The 'Subject:' header MUST be preserved.  The current Internet
  message format requires that only 7-bit US-ASCII characters be
  present.  Other characters MUST be encoded according to [Hdr-Enc].
  Note that it is possible for an [SMTP] extension to be defined that
  would permit transmission of unencoded 8-bit characters, but in the
  absence of such an extension, [Hdr-Enc] MUST be used.

  Resending

  A message may be resent to one or more new recipients.  It may be
  resent more than once, each time new 'Resent-' headers are added at
  the top of the existing headers.  Thus, if more than one series of
  'Resent-' headers are present, the original series is the last; the
  most recent is the first.

  Forward counter

  An 'X-Mms-Forward-Counter:' header, if present, SHOULD be removed.
  The 'Resent-Count:' header is NOT RECOMMENDED.  Loop control is
  usually done by counting 'Received' headers, which are more general
  than 'Resent-' headers.

  Previously-Sent Information

  MMS lists the resending history of a message in two headers:  'X-
  Mms-Previously-Sent-By:' and 'X-Mms-Previously-Sent-Date-and-Time:'.
  'X-Mms-Previously-Sent-By:'  contains a number followed by one or
  more addresses.  'X-Mms-Previously-Sent-Date-and-Time:' contains a
  number followed by a date-time.  With both headers, the number "0" is
  used for the entry that corresponds to the original submission of the
  message, with higher values being used for each subsequent resending.
  The final (most recent) resending information is in the 'From:' and
  'Date:' headers.  There is also an 'X-Mms-Forward-Counter:' that
  indicates how many times the message has been resent.

  Any 'X-Mms-Previously-Sent-By:', 'X-Mms-Previously-Sent-Date-and-
  Time:', and 'X-Mms-Forward-Counter:'  headers, if present, SHOULD be
  removed.  The information contained in them SHOULD be translated into
  [Msg-Fmt] headers as follows:

  The 'X-Mms-Previously-Sent-Date-and-Time:' header whose value starts
  with "0" SHOULD be used to create a 'Date:' header, converting the
  date and time from HTTP-date [HTTP] to date-time [Msg-Fmt].  The 'X-
  Mms-Previously-Sent-By:' header whose value starts with "0" SHOULD be
  used to create a 'From:' header.




Gellens                     Standards Track                    [Page 13]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  A 'To:' header SHOULD be created using list syntax with a value of
  "unrecoverable-recipients" and no mailboxes.

  A 'Message-ID:' header SHOULD be created.

  Any 'X-Mms-Previously-Sent-Date-and-Time:' headers whose value starts
  with "1" or a larger value are mapped to 'Resent-Date:'  headers.
  Any 'X-Mms-Previously-Sent-By:' headers whose value starts with "1"
  or a larger value are mapped to 'Resent-By:' headers.

  The 'From:', 'To:', 'Date:', and 'Message-ID:' headers are mapped to
  'Resent-From:', 'Resent-To:', 'Resent-Date:', and 'Resent-Message-
  ID:' headers in the top-most block of 'Resent-*' headers.

  Example:

  The MMS message:

  X-Mms-Forward-Counter: 2
  X-Mms-Previously-Sent-Date-and-Time: 0, Fri, 01 Apr 2005 06:02:03 GMT
  X-Mms-Previously-Sent-By:   0, General Failure <[email protected]>
  X-Mms-Previously-Sent-Date-and-Time: 1, Fri, 01 Apr 2005 08:02:03 GMT
  X-Mms-Previously-Sent-By:   1, Colonel Corn <[email protected]>
  Date:               Fri, 1 Apr 2005 18:02:03 -0800
  From:               L. Eva Message <[email protected]>
  To:                 [email protected]
  Message-ID:         <[email protected]>

  is mapped to an Internet mail message:

  Resent-Date: Fri, 1 Apr 2005 18:02:03 -0800
  Resent-From: L. Eva Message <[email protected]>
  Resent-To:   [email protected]
  Resent-Message-ID:  <[email protected]>
  Resent-Date: Fri, 1 Apr 2005 08:02:03 +0000
  Resent-From: Colonel Corn <[email protected]>
  Date:        Fri, 1 Apr 2005 06:02:03 +0000
  From:        General Failure <[email protected]>
  To:          Colonel Corn <[email protected]>
  Message-ID:  <[email protected]>

  'Received:' Headers

  When a message is gatewayed from MMS to Internet mail, a 'Received:'
  header MUST be added as per [SMTP].  The "with" clause should specify
  "MMS".





Gellens                     Standards Track                    [Page 14]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  A message MAY be rejected if the number of 'Received:' headers
  exceeds a locally-defined maximum, which MUST conform to [SMTP]
  Section 6.2 and SHOULD be no less than 100.

  Privacy

  Note that MMS systems do not currently support the 'Privacy' header
  field as described by [VPIM].

  Content

  The message content appears in the message body.  Note that Internet
  message format requires that line endings be encoded as US-ASCII CR
  LF octets; thus, charset encodings that do not have this property
  cannot be used in text/* body parts.  (They may be used in other body
  parts, but only when they are suitably encoded or when binary
  transmission has been negotiated, e.g., [BINARY].)  In particular,
  MMS allows UTF-16, whereas the Internet message format does not.
  UTF-16 encoding MUST be translated to UTF-8 or another charset and
  encoding that is suitable for use in Internet message
  format/protocols.

2.1.3.3.  Conversion of Messages from Internet to MMS Format

  3GPP MMS Version

  An 'X-Mms-3GPP-MMS-Version:' header SHOULD be added.

  Message Type (of PDU)

  An 'X-Mms-Message-Type:' header SHOULD be used in accordance with the
  specific MMS interface (e.g., MM1, MM4).

  Transaction ID

  An 'X-Mms-Transaction-Id:' header SHOULD be used in accordance with
  the specific MMS interface (e.g., MM1, MM4).

  Message ID

  The 'Message-Id:' header MUST be retained.  If not present, it MUST
  be created, with a unique value.

  Recipient(s) address

  'To:' and 'Cc:' headers MUST be retained.





Gellens                     Standards Track                    [Page 15]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Each recipient contained in the [SMTP] envelope (RCPT TO values) MUST
  be considered a recipient of the message.  Recipients who appear in
  address headers but not the [SMTP] envelope MUST be ignored.
  Recipients who appear in the [SMTP] envelope but do not appear in
  headers are considered "blind" (Bcc) recipients; such recipients MUST
  NOT be added to message headers (including address and trace headers)
  unless there is only one recipient total.

  Sender address

  The 'From:' header MUST be retained.

  Content type

  The complete 'Content-Type:' header (including any parameters) SHOULD
  be preserved.

  Message class

  An 'X-Mms-Message-Class: personal' header MAY be created for all
  received messages with a non-null return path (MAIL FROM value in the
  SMTP envelope).  An 'X-Mms-Message-Class: auto' header MAY be created
  for messages with a null return path.

  Time of Expiry

  An 'X-Mms-Expiry:' header SHOULD be created if the message contains a
  relative time to expiration in the DELIVER-BY extension with a by-
  mode of "R", as specified in [Deliver-By].

  If the by-mode is "N", a "relayed" DSN MUST be issued per
  [Deliver-By] and an 'X-Mms-Expiry:' header SHOULD NOT be created.

  Delivery report request

  An 'X-Mms-Delivery-Report:' header SHOULD be created for messages
  that request 'success' or 'none' delivery status notification by use
  of the DSN extension as specified in [DSN-SMTP].  Requests for
  'delay' notifications or non-default actions, such as that only the
  message headers should be returned, cannot be mapped onto MMS headers
  and thus SHOULD be ignored.










Gellens                     Standards Track                    [Page 16]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Importance

  The message sender's importance value (also called "priority",
  although this can be confused with class-of-service values) is
  expressed with an 'Importance:' header.  Historically, some clients
  used the older and non-standard 'X-Priority:' header for this
  purpose.  As a result, some clients generate both.

  An 'X-Priority:' or 'Importance:' header, if present, SHOULD be
  replaced with an 'X-Mms-Priority:' header.  If both headers are
  present, 'Importance:' SHOULD be used.  Suggested mappings are shown
  in Table 3:

2.1.3.3.1.  Table 3:  Priority Mappings (Internet Message to MMS)

     -------------------------------|----------------------
     'X-Priority: 1 (highest)'      |'X-Mms-Priority: High'
     -------------------------------|----------------------
     'X-Priority: 2 (high)'         |'X-Mms-Priority: High'
     -------------------------------|----------------------
     'Importance: High'             |'X-Mms-Priority: High'
     -------------------------------|----------------------
     'X-Priority: 3 (normal)'       |      [omitted]
     -------------------------------|----------------------
     'Importance: Normal'           |      [omitted]
     -------------------------------|----------------------
     'X-Priority: 4 (low)'          |'X-Mms-Priority: Low'
     -------------------------------|----------------------
     'Importance: Low'              |'X-Mms-Priority: Low'
     -------------------------------|----------------------
     'X-Priority: 5 (lowest)'       |'X-Mms-Priority: Low'
     -------------------------------|----------------------

  Normal importance messages SHOULD omit the 'X-Mms-Priority:' header.

  Sender visibility

  Support for sender address hiding is not currently supported.

  Read reply request

  A request for a read reply contained in a 'Disposition-Notification-
  To:' header as specified in [MDN] SHOULD be replaced with an 'X-Mms-
  Read-Reply:' header.

  Subject

  The 'Subject:' header MUST be preserved.



Gellens                     Standards Track                    [Page 17]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Resending

  Mapping from 'Resent-' and other [Msg-Fmt] headers to 'X-Mms-
  Previously-Sent-' headers SHOULD be done as follows:

  The original 'From:' header is mapped to an 'X-Mms-Previously-Sent-
  By:' header with a leading "0" value.  The value of the top-most
  'Resent-From:' header is mapped to the 'From:'  header.  The value of
  each subsequent 'Resent-From:' header is mapped to an 'X-Mms-
  Previously-Sent-By:' header with the next larger leading value.

  The original 'Date:' header is mapped to an 'X-Mms-Previously-Sent-
  Date-and-Time:' header with a leading "0" value.  Note that the value
  is also converted from date-time syntax [Msg-Fmt] to HTTP-date syntax
  [HTTP].  The value of the top-most 'Resent-Date:' header is mapped to
  the 'Date:' header.  The value of each subsequent 'Date:' header is
  mapped to an 'X-Mms-Previously-Sent-Date-and-Time:' header with the
  next larger leading value.

  If one or more 'Resent-Message-ID:' headers are present, the top-most
  one SHOULD be mapped to 'Message-ID:'; otherwise, the 'Message-ID:'
  header should be retained.

  An 'X-Mms-Forward-Counter:' header SHOULD be created when 'Resent-'
  headers have been mapped to 'X-Mms-Previously-Sent-' headers.  Its
  value SHOULD be the number of 'Resent-' blocks that existed prior to
  mapping.

  Example:

  The original message:

  Date:        Fri, 1 Apr 2005 14:02:03 -0800
  From:        General Failure <[email protected]>
  To:          Colonel Corn <[email protected]>
  Message-ID:  <[email protected]>

  Is resent by Colonel Corn to L. Eva Message:

  Resent-Date: Fri, 1 Apr 2005 16:02:03 -0800
  Resent-From: Colonel Corn <[email protected]>
  Resent-To:   L. Eva Message <[email protected]>
  Resent-Message-ID:  <[email protected]>
  Date:        Fri, 1 Apr 2005 14:02:03 -0800
  From:        General Failure <[email protected]>
  To:          Colonel Corn <[email protected]>
  Message-ID:  <[email protected]>




Gellens                     Standards Track                    [Page 18]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  L. Eva then resends to her MMS device:

  Resent-Date: Fri, 1 Apr 2005 18:02:03 -0800
  Resent-From: L. Eva Message <[email protected]>
  Resent-To:   [email protected]
  Resent-Message-ID:  <[email protected]>
  Resent-Date: Fri, 1 Apr 2005 16:02:03 -0800
  Resent-From: Colonel Corn <[email protected]>
  Resent-To:   L. Eva Message <[email protected]>
  Resent-Message-ID:  <[email protected]>
  Date:        Fri, 1 Apr 2005 14:02:03 -0800
  From:        General Failure <[email protected]>
  To:          Colonel Corn <[email protected]>
  Message-ID:  <[email protected]>

  This would be mapped to an MMS message as:

  X-Mms-Forward-Counter: 2
  X-Mms-Previously-Sent-Date-and-Time: 0, Fri, 01 Apr 2005 06:02:03 GMT
  X-Mms-Previously-Sent-By:   0, General Failure <[email protected]>
  X-Mms-Previously-Sent-Date-and-Time: 1, Fri, 01 Apr 2005 08:02:03 GMT
  X-Mms-Previously-Sent-By:   1, Colonel Corn <[email protected]>
  Date:               Fri, 1 Apr 2005 18:02:03 -0800
  From:               L. Eva Message <[email protected]>
  To:                 [email protected]
  Message-ID:         <[email protected]>

  Note that the original 'From:' and 'Date:' values were moved to 'X-
  Mms-Previously-Sent-By:' and 'X-Mms-Previously-Sent-Date-and-Time:'
  headers with a leading "0" value.  The first 'Resent-From:' and
  'Resent-Date:' values were moved to a second set of 'X-Mms-
  Previously-Sent-' headers, with a leading "1" value.  The third set
  of 'Resent-' headers were moved to the 'Date:', 'To:', and 'From:'
  headers.

  Note also that the format of the date and time differs between the
  'Date:' / 'Resent-Date:' and the 'X-Mms-Previously-Sent-Date-and-
  Time:' headers, in that the latter use HTTP-date [HTTP] instead of
  date-time [Msg-Fmt].

  'Received:' Headers

  Each system that processes a message SHOULD add a 'Received:' header
  as per [SMTP].  A message MAY be rejected if the number of
  'Received:' headers exceeds a locally-defined maximum, which MUST
  conform to [SMTP] Section 6.2 and SHOULD be no less than 100.





Gellens                     Standards Track                    [Page 19]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  Sensitivity

  The 'Sensitivity:' header field (value = "personal" or "private")
  [VPIM] indicates the desire of a voice message originator to send the
  message contents to the original recipient list with assurance that
  the message will not be forwarded further by either the messaging
  system or the actual message recipient(s).  Since sensitivity is not
  an MMS feature, any messages that contain a 'Sensitivity:' header
  MUST NOT be sent to an MMS system.  The associated negative delivery
  status report MUST include the extended status code [RESP] 5.6.0 as
  specified in [VPIM] ("Other or undefined protocol status") indicating
  that privacy could not be ensured.

  Content

  The message content appears in the message body.

2.1.4.  Report Generation and Conversion

  Internet message systems use the multipart/report MIME type for
  delivery and disposition reports as specified in [Report-Fmt].  This
  format is a two- or three-part MIME message; one part is a structured
  format describing the event being reported in an easy-to-parse
  format.  Specific reports have a format that is built on
  [Report-Fmt].  Delivery reports are specified in [DSN-Msg].  Message
  disposition reports, which include read reports, are specified in
  [MDN].

  By contrast, MMS reports are plain text, with no defined structure
  specified.  This makes it difficult to convert from an MMS report to
  a standard Internet report.

  An implementation conforming to this specification MUST convert
  reports received from one side (MMS or Internet mail) destined for
  the other.  In addition, reports MUST be generated as appropriate for
  messages received from either side.  For example, if an MM to be sent
  via Internet mail is not deliverable, a delivery status MM shall be
  generated.  Likewise, if an Internet message is received that cannot
  be further relayed or delivered, a delivery status report [DSN-Msg]
  MUST be generated.

  When creating delivery or disposition reports from MMS reports, the
  MMS report should be parsed to determine the reported event and time,
  status, and the headers of the referenced (original) message.  These
  elements, once determined, are used to populate the subparts of the
  delivery or disposition report.  The first subpart is of type
  text/plain, and contains a human-readable explanation of the event.
  This text may include a statement that the report was synthesized



Gellens                     Standards Track                    [Page 20]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  based on an MMS report.  The second subpart is of type
  report/delivery-status (for delivery reports) or report/disposition-
  notification (for disposition reports).  This second part contains a
  structured itemization of the event.  The optional third subpart is
  of type message/rfc822 and includes the headers and optionally the
  body of the referenced (original) message.  Note that, per [DSN-Msg],
  the 'DSN-Gateway:' field in delivery reports MUST be created.

2.1.4.1.  Delivery Report Mapping from MMS to Internet Message

  Below, Table 4 maps information elements from MMS delivery reports to
  the format specified in [DSN-Msg].

2.1.4.1.1.  Table 4:  Delivery Report Mappings (MMS to Internet Message)

======================|============|===================================
Information Element   |MMS Delivery|[DSN-Msg] Element
                     |Report Elem |
======================|============|===================================
ID of message whose   |Message-Id: |'Message-ID:' preserved in third
delivery status is    |            |subpart of delivery report.
being reported        |            |
----------------------|------------|-----------------------------------
Recipient address of  |From:       |'Final-Recipient' field of the
the original message  |            |per-recipient section.
(object of delivery   |            |
report)               |            |
----------------------|------------|-----------------------------------
Destination address of|To:         |'To:' header field value of top-
report                |            |level.
----------------------|------------|-----------------------------------
Date and time the     |Date:       |'Date:' header field value of top-
message was handled   |            |level.
----------------------|------------|-----------------------------------

















Gellens                     Standards Track                    [Page 21]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


======================|============|===================================
Information Element   |MMS Delivery|[DSN-Msg] Element
                     |Report Elem |
======================|============|===================================
Delivery status of    |X-Mms-      |Action and Status fields of
original message to   |   Status:  |per-recipient section.
each recipient        |            |
                     |            |The 'Action' field indicates if the
                     |            |message was delivered.
                     |            |
                     |            |For failed delivery, an appropriate
                     |            |'Status' value shall be included
                     |            |per [DSN-Msg].
                     |            |
                     |            |The Action field is set to one of
                     |            |the following values:
                     |            |
                     |            |* delivered (used for MMS status
                     |            |values 'retrieved' and 'rejected',
                     |            |depending on 'Status' code).
                     |            |
                     |            |* failed (used for MMS status
                     |            |values 'expired' and 'unreachable')
                     |            |
                     |            |* delayed MAY be used for MMS
                     |            |status value 'deferred'
                     |            |
                     |            |* relayed (used for MMS status
                     |            |value 'indeterminate')
                     |            |
                     |            |* expanded (SHOULD NOT be used)
----------------------|------------|-----------------------------------
Status Text           |            |Text in first part (human-readable
                     |            |part).
----------------------|------------|-----------------------------------

  When an MMS Relay/Server generates a [DSN-Msg] in response to a
  message received using [SMTP] on MM3:

  * Top-level header field 'To:' SHOULD be the [SMTP] return-path of
    the message whose status is being reported.

  * Top-level header field 'From:' SHOULD be the address of the
    recipient that the delivery-report concerns.

  * The first part of the [DSN-Msg] SHOULD include the MM Status Text
    field that would have been generated for an MM1 delivery-report.




Gellens                     Standards Track                    [Page 22]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


2.1.4.2 Delivery Report Mapping from Internet Message to MMS

  Below, Table 5 maps information elements from a delivery report as
  specified in [DSN-Msg] to the format of an MMS delivery report.  Note
  that a single DSN that reports multiple recipients will result in
  several MMS delivery reports.

2.1.4.2.1.  Table 5:  Delivery Report Mappings (Internet Message to MMS)

===================|==================|================================
Information Element|MMS Delivery      |[DSN-Msg] Element
                  |Report Element    |
===================|==================|================================
ID of the original |Message-Id:       |'Message-ID:' header preserved
message (object of |                  |in third sub-part of report.
delivery report)   |                  |
-------------------|------------------|--------------------------------
Recipient address  |From:             |If available, the 'Original
of the original    |                  |-Recipient' field of the per-
message (object of |                  |recipient section should be
delivery report)   |                  |used; otherwise, the 'Final-
                  |                  |Recipient' field of the per-
                  |                  |recipient section is used.
-------------------|------------------|--------------------------------
Destination address|To:               |'To:' header field value of
of report          |                  |top-level.
                  |                  |
                  |                  |Value taken from [SMTP] envelope
                  |                  |return-path of message being
                  |                  |reported, not its 'From:' header
                  |                  |field.
-------------------|------------------|--------------------------------
Date and time the  |Date:             |'Date:' header field value of
message was handled|                  |top-level.
-------------------|------------------|--------------------------------
















Gellens                     Standards Track                    [Page 23]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


===================|==================|================================
Information Element|MMS Delivery      |[DSN-Msg] Element
                  |Report Element    |
===================|==================|================================
Delivery status of |X-Mms-Status:     |'Action' and 'Status' fields of
original message   |                  |per-recipient section.
                  |Set to one of the |
                  |following values: |
                  |                  |
                  |'retrieved' (used |
                  |for 'Action' value|
                  |'delivered').     |
                  |                  |
                  |'unreachable'     |
                  |(used for 'Action'|
                  |value 'failed')   |
                  |                  |
                  |'forwarded' (used |
                  |for 'Action' value|
                  |'relayed')        |
                  |                  |
                  |'deferred' MUST   |
                  |NOT be used       |
                  |(ignore DSNs with |
                  |'Action' value    |
                  |'delayed')        |
-------------------|------------------|--------------------------------
Status Text        |                  |Text in first part (human-
                  |                  |readable part).
===================|==================|================================

2.1.4.3.  Read Report Mapping from MMS to Internet Message

  Below, Table 6 maps information elements from MMS read reports to the
  format specified in [MDN].

2.1.4.3.1.  Table 6:  Read Report Mappings (MMS to Internet Message)

======================|============|===================================
Information Element   |MMS Delivery|[MDN] Element
                     |Report Elem |
======================|============|===================================
ID of the original    |Message-Id: |'Message-ID:' header preserved in
message (object of    |            |third part of report.
read report)          |            |
----------------------|------------|-----------------------------------
Recipient address of  |From:       |'Final-Recipient' field.
the original message  |            |



Gellens                     Standards Track                    [Page 24]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


======================|============|===================================
Information Element   |MMS Delivery|[MDN] Element
                     |Report Elem |
======================|============|===================================
Destination address of|To:         |'To:' header field value of top-
report                |            |level.
                     |            |
                     |            |Value taken from 'Disposition-
                     |            |Notification-To:' header field of
                     |            |message being reported, not its
                     |            |'From:' header field.
----------------------|------------|-----------------------------------
Date and time the     |Date:       |'Date:' header field value of top-
message was handled   |            |level.
----------------------|------------|-----------------------------------
Disposition of message|X-Mms-Read- |Disposition-field
being reported        |   Status:  |
                     |            |For X-MMS-Read-Status value 'read',
                     |            |use 'disposition-type' value
                     |            |'displayed'; for X-MMS-Read-Status
                     |            |value 'Deleted without being read',
                     |            |use 'disposition-type' value
                     |            |'deleted').
----------------------|------------|-----------------------------------
Status Text           |            |Text in first part (human-readable
                     |            |part).
======================|============|===================================

  When an MMS Relay/Server generates an [MDN] in response to a message
  received using [SMTP] on MM3:

  * Top-level header field 'To:' SHOULD be the value of the
    'Disposition-Notification-To:' header field of the message whose
    disposition is being reported.

  * Top-level header field 'From:' SHOULD be the address of the
    recipient that the read report concerns.

2.1.4.4.  Disposition Report Mapping from Internet Message to MMS

  Below, Table 7 maps information elements from a disposition report as
  specified in [MDN] to the format of an MMS read report.









Gellens                     Standards Track                    [Page 25]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


2.1.4.4.1.  Table 7:  Disposition Report Mappings
                     (Internet Message to MMS)

===================|==================|================================
Information Element|MMS Read Report   |[MDN] Element
                  |Element           |
===================|==================|================================
ID of the original |Message-Id:       |'Message-ID:' header preserved
message (object of |                  |in third subpart of report.
disposition report)|                  |
-------------------|------------------|--------------------------------
Recipient address  |From:             |'Final-Recipient' field.
of the original    |                  |
message            |                  |
-------------------|------------------|--------------------------------
Destination address|To:               |'To:' header field value of
of report          |                  |top-level.
                  |                  |
                  |                  |Value taken from 'Disposition-
                  |                  |Notification-To:' header field
                  |                  |of message being reported, not
                  |                  |its 'From:' header field.
-------------------|------------------|--------------------------------
Date and time the  |Date:             |'Date:' header field value of
message was handled|                  |top-level.
-------------------|------------------|--------------------------------
Disposition of     |X-Mms-Read-Status:|disposition-field.
message being      |                  |
reported           |Set to one of the |
                  |following values: |
                  |                  |
                  |'read' (used for  |
                  |disposition-type  |
                  |value 'displayed')|
                  |                  |
                  |'Deleted without  |
                  |being read' (used |
                  |for disposition-  |
                  |types 'deleted',  |
                  |'denied' and      |
                  |'failed' when     |
                  |action-mode is    |
                  |'automatic-       |
                  |action')          |
-------------------|------------------|--------------------------------
Status Text        |                  |Text in first part (human-
                  |                  |readable part).
===================|==================|================================



Gellens                     Standards Track                    [Page 26]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006



2.1.5.  Message Delivery

  Within Internet mail, when [SMTP] is used and delivery reports are
  requested [DSN-SMTP], delivery is considered to be acceptance of a
  message by the final server, that is, the server closest to the
  recipient.  When an MMS Relay/Server receives a message using [SMTP]
  and a delivery report is requested, the MMS Relay/Server MAY consider
  the message delivered when it has been sent to the MMS User Agent.

3.  Security Considerations

  Both MMS and Internet mail have their own set of security risks and
  considerations.  This document specifies how to exchange messages
  between these two environments, so it is only appropriate to discuss
  considerations specific to this functionality, not those inherent in
  either environment.

  When a message uses end-to-end security mechanisms such as [PGP] or
  S/MIME [SMIME], servers MUST be careful not to accidently destroy the
  integrity of the protected content (for example, by altering any text
  within the region covered by a signature while mapping between MMS
  and email).  [Mime-Sec-gw] discusses issues with use of such
  mechanisms in gateways.

  Some MMS features contain inherently more risk than others, including
  reply charging and sender address hiding.  Support for these
  mechanisms is not included in this document.

4.  IANA Considerations

  IANA has added "MMS" as one of the "WITH protocol types" under its
  "MAIL Parameters" registry.  The description is "Multimedia Messaging
  Service"; the reference is to this document.

5.  Acknowledgements

  A number of people contributed to this document, especially the
  members of the IETF Lemonade working group, including Greg Vaudreuil.
  John Klensin did a very thorough and helpful review.  Greg White
  caught a large number of nits.  Ted Hardie was very helpful.  Alexey
  Melnikov and Chris Newman sent very useful and detailed comments.

6.  Normative References

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



Gellens                     Standards Track                    [Page 27]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


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

  [Hdr-Enc]     Moore, K., "MIME (Multipurpose Internet Mail
                Extensions) Part Three: Message Header Extensions for
                Non-ASCII Text ", RFC 2047, November 1996.

  [HTTP]        Fielding,  R., Gettys, J., Mogul, J., Frystyk, H.,
                Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
                Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.

  [IDN]         Faltstrom, P., Hoffman, P., and A. Costello,
                "Internationalizing Domain Names in Applications
                (IDNA)", RFC 3490, March 2003.

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

  [MDN]         Hansen, T. and G. Vaudreuil, "Message Disposition
                Notification", RFC 3798, May 2004.

  [Msg-Fmt]     Resnick, P., "Internet Message Format", RFC 2822, April
                2001.

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

  [RESP]        Vaudreuil, G., "Enhanced Mail System Status Codes", RFC
                3463, January 2003.

  [SMTP]        Klensin, J., "Simple Mail Transfer Protocol", RFC 2821,
                April 2001.

  [OMA]         OMA specifications are available at the OMA web site
                <http://www.openmobilealliance.org>.

  [OMA-MMS]     OMA-WAP-MMS-ENC-V1_2-20040323-C

  [3GPP2]       3GPP2 specifications are available at the 3GPP2 (Third
                Generation Partnership Project 2) web site
                <http://www.3gpp2.org>.

  [3GPP]        3GPP specifications are available at the 3GPP (Third
                Generation Partnership Project) web site
                <http://www.3gpp.org>




Gellens                     Standards Track                    [Page 28]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


  [Stage_3]     "MMS MM1 Stage 3 using OMA/WAP", X.S0016-310

                "MMS MM4 Stage 3 Inter-Carrier Interworking", X.S0016-
                340

                "Multimedia Messaging Service:  Functional description;
                Stage 2", TS 23.140 Release 5.

7.  Informative References

  [BINARY]      Vaudreuil, G., "SMTP Service Extensions for
                Transmission of Large and Binary MIME Messages", RFC
                3030, December 2000.

  [Deliver-By]  Newman, D., "Deliver By SMTP Service Extension", RFC
                2852, June 2000.

  [Hdrs]        Palme, J., "Common Internet Message Headers", RFC 2076,
                February 1997.

  [Mime-Sec-gw] Freed, N., "Gateways and MIME Security Multiparts", RFC
                2480, January 1999.

  [PGP]         Elkins, M., Del Torto, D., Levien, R., and T. Roessler,
                "MIME Security with OpenPGP", RFC 3156, August 2001.

  [SMIME]       Ramsdell, B., "Secure/Multipurpose Internet Mail
                Extensions (S/MIME) Version 3.1 Message Specification",
                RFC 3851, July 2004.

  [Submission]  Gellens, R. and J. Klensin, "Message Submission", RFC
                2476, December 1998.

  [VPIM]        Vaudreuil, G. and G. Parsons, "Voice Profile for
                Internet Mail - version 2 (VPIMv2)", RFC 3801, June
                2004.

  [Overview]    "Multimedia Messaging Services (MMS) Overview",
                X.S0016-000

  [Stage_1]     "Multimedia Messaging Services (MMS); Stage 1",
                Requirements, October 2002, S.R0064-0.

  [Stage_2]     "Multimedia Messaging Service (MMS); Stage 2",
                Functional Specification, April 2003, X.S0016-200.

                "Multimedia Messaging Service; Media formats and
                codecs", TS26.140Release 5.



Gellens                     Standards Track                    [Page 29]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


Author's Address

  Randall Gellens
  QUALCOMM Incorporated
  5775 Morehouse Drive
  San Diego, CA  92121

  EMail: [email protected]











































Gellens                     Standards Track                    [Page 30]

RFC 4356         Mapping Between MMS and Internet Mail      January 2006


Full Copyright Statement

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  contained in BCP 78, and except as set forth therein, the authors
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Gellens                     Standards Track                    [Page 31]