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Post-Delivery Message Downgrading for Internationalized Email Messages
RFC 6857

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    eai mailing list <>,
    eai chair <>
Subject: Protocol Action: 'Post-delivery Message Downgrading for Internationalized Email Messages' to Proposed Standard (draft-ietf-eai-popimap-downgrade-08.txt)

The IESG has approved the following document:
- 'Post-delivery Message Downgrading for Internationalized Email
  (draft-ietf-eai-popimap-downgrade-08.txt) as Proposed Standard

This document is the product of the Email Address Internationalization
Working Group.

The IESG contact persons are Pete Resnick and Barry Leiba.

A URL of this Internet Draft is:

Ballot Text

[Please note: This document is one a set of four interdependent


These documents should be reviewed, evaluated, and understood

   Technical Summary

      The Email Address Internationalization (SMTPUTF8) extension to
      SMTP allows UTF-8 characters in mail header fields.  Upgraded POP
      and IMAP servers support internationalized Email messages. If a
      POP/IMAP client does not support Email Address
      Internationalization, POP/IMAP servers cannot deliver
      Internationalized Email Headers to the client and cannot remove
      the message.  To avoid the situation, this document describes a
      conversion mechanism for internationalized Email messages to be in
      traditional message format.  In the process, message elements
      requiring internationalized treatment are recoded or removed and
      receivers are able to know that they received messages containing
      such elements even if they cannot process the internationalized

   Working Group Summary

      No particular process issues of note. The WG had extensive and
      constructive discussions about the role of "downgrading" (e.g.,
      converting a message stored on the server that contains non-ASCII
      header or envelope information) in the transition to an all-i18n
      environment.  Some of those issues and tradeoffs are discussed in
      draft-ietf-eai-popimap-downgrade and
      draft-ietf-eai-simpledowngrade.  In some cases, the best strategy
      may be to "hide" those messages that cannot be delivered without
      change to legacy clients either with or without some attempt at an
      error message.  A complete treatment of those options is
      impossible because the optimal strategies will depend considerably
      on local circumstances.  Consequently the base IMAP and POP3
      documents are no longer dependent on particular downgrading
      choices and that two methods presented are, to a considerable
      extent, just examples.  They are recommended as alternative
      Standards Track documents because they are protocol specifications
      and their sometimes-subtle details have have been carefully worked
      out, even though the WG has no general recommendation to make
      between them (or other strategies).

      While opinions differ in the WG about which downgrading mechanisms
      are likely to see the most use, if any, consensus is strong that
      these four documents represent the correct output.

   Document Quality

      Some development and interoperability testing has occurred and is
      progressing.  There are strong commitments in various countries to
      implement and deploy the EAI (more properly, SMTPUTF8) messages
      and functions specified in RFCs 6530 through 6533.  Those messages
      will be inaccessible to many users without POP3 and IMAP support,
      so these specifications are quite likely to be implemented and
      deployed in a timely fashion.

      Reviewers who made particular contributions prior to IETF Last
      Call are acknowledged in the documents.  See Section 3 for
      additional information.


      Document Shepherd:   John C Klensin
      Responsible Area Director:   Pete Resnick

   RFC Editor Note

   This procedure may generate empty <group> elements in
   "From:", "Sender:" and "Reply-To:" header fields.
   [I-D.leiba-5322upd-from-group] updates [RFC5322] to allow
   (empty) <group> elements in "From:", "Sender:" and
   "Reply-To:" header fields.

   This procedure may generate empty <group> elements in
   "From:",    "Sender:" and "Reply-To:" header fields.
   [I-D.leiba-5322upd-from-group] updates [RFC5322] to allow
   (empty) <group> elements in "From:" and "Sender:".

RFC Editor Note