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Versions: 00 01 02 03 04 05 06 07 08 09 RFC 5738

Network Working Group                                         P. Resnick
Internet-Draft                                     Qualcomm Incorporated
Updates: 3501 (if approved)                                    C. Newman
Intended status: Experimental                           Sun Microsystems
Expires: March 9, 2010                                 September 5, 2009


                         IMAP Support for UTF-8
                      draft-ietf-eai-imap-utf8-08

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Copyright Notice

   Copyright (c) 2009 IETF Trust and the persons identified as the
   document authors.  All rights reserved.




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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents in effect on the date of
   publication of this document (http://trustee.ietf.org/license-info).
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.

Abstract

   This specification extends the Internet Message Access Protocol
   version 4rev1 (IMAP4rev1) to support unencoded international
   characters in user names, mail addresses and message headers.


Table of Contents

   1.  Conventions Used in this Document  . . . . . . . . . . . . . .  3
   2.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  UTF8 IMAP Capability . . . . . . . . . . . . . . . . . . . . .  3
     3.1.  IMAP UTF-8 Quoted Strings  . . . . . . . . . . . . . . . .  3
     3.2.  UTF8 Parameter to SELECT and EXAMINE . . . . . . . . . . .  5
     3.3.  UTF-8 LIST and LSUB Responses  . . . . . . . . . . . . . .  5
     3.4.  UTF-8 Interaction with IMAP4 LIST Command Extensions . . .  6
       3.4.1.  UTF8 and UTF8ONLY LIST Selection Options . . . . . . .  6
       3.4.2.  UTF8 LIST Return Option  . . . . . . . . . . . . . . .  6
   4.  UTF8=APPEND Capability . . . . . . . . . . . . . . . . . . . .  7
   5.  UTF8=USER Capability . . . . . . . . . . . . . . . . . . . . .  7
   6.  UTF8=ALL Capability  . . . . . . . . . . . . . . . . . . . . .  7
   7.  UTF8=ONLY Capability . . . . . . . . . . . . . . . . . . . . .  7
   8.  Up-Conversion Server Requirements  . . . . . . . . . . . . . .  8
   9.  Issues with UTF-8 Header Mailstore . . . . . . . . . . . . . .  9
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
   11. Security Considerations  . . . . . . . . . . . . . . . . . . . 11
   12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
     12.1. Normative References . . . . . . . . . . . . . . . . . . . 11
     12.2. Informative References . . . . . . . . . . . . . . . . . . 12
   Appendix A.  Design Rationale  . . . . . . . . . . . . . . . . . . 13
   Appendix B.  Acknowledgments . . . . . . . . . . . . . . . . . . . 14
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14













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1.  Conventions Used in this Document

   The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY"
   in this document are to be interpreted as defined in "Key words for
   use in RFCs to Indicate Requirement Levels" [RFC2119].

   The formal syntax use the Augmented Backus-Naur Form (ABNF) [RFC5234]
   notation including the core rules defined in Appendix B of RFC 4234.
   In addition, rules from IMAP4rev1 [RFC3501], UTF-8 [RFC3629],
   Collected extensions to IMAP4 ABNF [RFC4466], and IMAP4 LIST Command
   Extensions [RFC5258] are also referenced.

   In examples, "C:" and "S:" indicate lines sent by the client and
   server respectively.  If a single "C:" or "S:" label applies to
   multiple lines, then the line breaks between those lines are for
   editorial clarity only and are not part of the actual protocol
   exchange.


2.  Introduction

   This specification extends IMAP4rev1 [RFC3501] to permit unencoded
   UTF-8 [RFC3629] in headers as described in Internationalized Email
   Headers [RFC5335].  It also adds a mechanism to support mailbox
   names, login names and passwords using the UTF-8 charset.  This
   specification creates five new IMAP capabilities to allow servers to
   advertise these new extensions, along with two new IMAP list
   extensions and a new IMAP list return option.


3.  UTF8 IMAP Capability

   The basic "UTF8" capability indicates the server supports UTF-8
   quoted strings, the "UTF8" parameter to SELECT and EXAMINE, and UTF-8
   responses from the LIST and LSUB commands.

   A client MUST use the "ENABLE UTF8" command (defined in [RFC5161]) to
   indicate to the server that the client accepts UTF-8 quoted-strings.
   The "ENABLE UTF8" command MUST only be used in the authenticated
   state.

3.1.  IMAP UTF-8 Quoted Strings

   The IMAP4rev1 [RFC3501] base specification forbids the use of 8-bit
   characters in atoms or quoted strings.  Thus a UTF-8 string can only
   be sent as a literal.  This can be inconvenient from a coding
   standpoint, and unless the server offers IMAP4 non-synchronizing
   literals [RFC2088], this requires an extra round trip for each UTF-8



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   string sent by the client.  When the IMAP server advertises the
   "UTF8" capability, it informs the client that it supports native
   UTF-8 quoted-strings with the following syntax:

     string        =/ utf8-quoted

     utf8-quoted   = "*" DQUOTE *UQUOTED-CHAR DQUOTE

     UQUOTED-CHAR  = QUOTED-CHAR / UTF8-2 / UTF8-3 / UTF8-4
                ; UTF8-2, UTF8-3, and UTF8-4 are as defined in RFC 3629

   When this quoting mechanism is used by the client (specifically an
   octet sequence beginning with *" and ending with "), then the server
   MUST reject octet sequences with the high bit set that fail to comply
   with the formal syntax in [RFC3629] with a BAD response.

   The IMAP server MUST NOT send utf8-quoted syntax to the client unless
   the client has indicated support for that syntax by using the "ENABLE
   UTF8" command.

   If the server advertises the UTF8 capability, the client MAY use
   utf8-quoted syntax with any IMAP argument that permits a string
   (including astring and nstring).  However, if characters outside the
   US-ASCII repertoire are used in an inappropriate place, the results
   would be the same as if other syntacticly valid but semantically
   invalid characters were used.  For example, if the client includes
   UTF-8 characters in the user or password arguments (and the server
   has not advertised UTF8-USER), the LOGIN command will fail as it
   would with any other invalid user name or password.  Specific cases
   where UTF-8 characters are permitted or not permitted are described
   in the following paragraphs.

   All IMAP servers that advertise the UTF8 capability SHOULD accept
   UTF-8 in mailbox names, and those that also support the "Mailbox
   International Naming Convention" described in RFC 3501 section 5.1.3
   MUST accept utf8-quoted mailbox names and convert them to the
   appropriate internal format.  Mailbox names MUST comply with the Net-
   Unicode Definition (section 2 of [RFC5198]) with the specific
   exception that they MUST NOT contain control characters (0000-001F,
   0080-009F), delete (007F), line separator (2028) or paragraph
   separator (2029).

   An IMAP client MUST NOT issue a SEARCH command that uses a mixture of
   utf8-quoted syntax and a SEARCH CHARSET other than UTF-8.  If an IMAP
   server receives such a SEARCH command, it SHOULD reject the command
   with a BAD response (due to the conflicting charset labels).





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3.2.  UTF8 Parameter to SELECT and EXAMINE

   The "UTF8" capability also indicates the server supports the UTF8
   parameter to SELECT and EXAMINE.  When a mailbox is selected with the
   UTF8 parameter, it alters the behavior of all IMAP commands related
   to message sizes, message headers and MIME body headers so they refer
   to the message with UTF-8 headers.  If the mailstore is not UTF-8
   header native and the SELECT or EXAMINE command with UTF-8 header
   modifier succeeds, then the server MUST return results as if the
   mailstore was UTF-8 header native with upconversion requirements as
   described in Section 8.  The server MAY reject the SELECT or EXAMINE
   command with the [NOT-UTF-8] response code, unless the UTF8=ALL or
   UTF8=ONLY capability is advertised.

   Servers MAY include mailboxes that can only be selected or examined
   if the UTF8 parameter is provided.  However, such mailboxes MUST NOT
   be included in the output of an unextended LIST, LSUB or equivalent
   command.  If a client attempts to SELECT or EXAMINE such mailboxes
   without the UTF8 parameter, the server MUST reject the command with a
   [UTF-8-ONLY] response code.  As a result, such mailboxes will not
   accessible by IMAP clients written prior to this specification and
   are discouraged unless the server advertises UTF8=ONLY or the server
   implements IMAP4 LIST Command Extensions [RFC5258].

     utf8-select-param = "UTF8"
               ;; Conforms to <select-param> from RFC 4466


     C: a SELECT newmailbox (UTF8)
     S: ...
     S: a OK SELECT completed
     C: b FETCH 1 (SIZE ENVELOPE BODY)
     S: ... < UTF-8 header native results >
     S: b OK FETCH completed

     C: c EXAMINE legacymailbox (UTF8)
     S: c NO [NOT-UTF-8] Mailbox does not support UTF-8 access

     C: d SELECT funky-new-mailbox
     S: d NO [UTF-8-ONLY] Mailbox requires UTF-8 client

3.3.  UTF-8 LIST and LSUB Responses

   After an IMAP client successfully issues an "ENABLE UTF8" command,
   the server MUST NOT return in LIST results any mailbox names to the
   client following the IMAP4 Mailbox International Naming Convention.
   Instead, the server MUST return any mailbox names with characters
   outside the US-ASCII repertoire using utf8-quoted syntax.  (The IMAP4



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   Mailbox International Naming Convention has proved problematic in the
   past, so the desire is to make this syntax obsolete as quickly as
   possible.)

3.4.  UTF-8 Interaction with IMAP4 LIST Command Extensions

   When an IMAP server advertises both the "UTF8" capability and the
   "LIST-EXTENEDED" [RFC5258] capability, the server MUST support the
   LIST extensions described in this section.

3.4.1.  UTF8 and UTF8ONLY LIST Selection Options

   The UTF8 LIST selection option tells the server to include mailboxes
   that only support UTF-8 headers in the output of the list command.
   The UTF8ONLY LIST selection option tells the server to include all
   mailboxes that support UTF-8 headers and to exclude mailboxes that
   don't support UTF-8 headers.  Note that UTF8ONLY implies UTF8 so it
   is not necessary for the client to request both.  Use of either
   selection option will also result in UTF-8 mailbox names in the
   result as described in Section 3.3 and implies the UTF8 List return
   option described in Section 3.4.2.

3.4.2.  UTF8 LIST Return Option

   If the client supplies the UTF8 LIST return option, then the server
   MUST include either the \NoUTF8 or the \UTF8Only mailbox attribute as
   appropriate.  The \NoUTF8 mailbox attribute indicates an attempt to
   SELECT or EXAMINE that mailbox with the UTF8 parameter will fail with
   a [NOT-UTF-8] response code.  The \UTF8Only mailbox attribute
   indicates an attempt to SELECT or EXAMINE that mailbox without the
   UTF8 parameter will fail with a [UTF-8-ONLY] response code.  Note
   that computing this information may be expensive on some server
   implementations so this return option should not be used unless
   necessary.

   The ABNF [RFC5234] for these LIST extensions follows:

     list-select-independent-opt =/ "UTF8"

     list-select-base-opt        =/ "UTF8ONLY"

     mbx-list-oflag              =/ "\NoUTF8" / "\UTF8Only"

     return-option               =/ "UTF8"

     resp-text-code              =/ "NOT-UTF-8" / "UTF-8-ONLY"





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4.  UTF8=APPEND Capability

   If the UTF8=APPEND capability is advertised, then the server accepts
   UTF-8 headers in the APPEND command message argument.  A client that
   sends a message with UTF-8 headers to the server MUST send them using
   the UTF8 APPEND data extension.  If the server also advertises the
   CATENATE capability (as specified in [RFC4469]), the client can use
   the same data extension to include such a message in a CATENATE
   message part.  The ABNF for the APPEND data extension and CATENATE
   extension follows:

     utf8-literal   = "UTF8" SP "(" literal8 ")"

     append-data    =/ utf8-literal

     cat-part       =/ utf8-literal

   A server that advertises UTF8=APPEND has to comply with the
   requirements of the IMAP base specification and [RFC5322] for message
   fetching.  Mechanisms for 7-bit downgrading to help comply with the
   standards are discussed in Downgrading mechanism for
   Internationalized eMail Address (IMA) [RFC5504].

   IMAP servers that do not advertise the UTF8=APPEND or UTF8=ONLY
   capability SHOULD reject an APPEND command that includes any 8-bit in
   the message headers with a "NO" response.


5.  UTF8=USER Capability

   If the UTF8=USER capability is advertised, that indicates the server
   accepts UTF-8 user names and passwords and applies SASLprep [RFC4013]
   to both arguments of the LOGIN command.  The server MUST reject UTF-8
   that fails to comply with the formal syntax in RFC 3629 [RFC3629].


6.  UTF8=ALL Capability

   This capability indicates all server mailboxes support UTF-8 headers.
   Specifically, SELECT and EXAMINE with the UTF8 parameter will never
   fail with a [NOT-UTF-8] response code.


7.  UTF8=ONLY Capability

   This capability permits an IMAP server to advertise that it does not
   support the international mailbox name convention (modified UTF-7),
   and does not permit selection or examination of any mailbox unless



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   the UTF8 parameter is provided.  As this is an incompatible change to
   IMAP, a clear warning is necessary.  IMAP clients that find
   implementation of the UTF8 capability problematic are encouraged to
   at least detect the UTF8=ONLY capability and provide an informative
   error message to the end-user.

   When an IMAP mailbox internally uses UTF-8 header native storage, the
   down-conversion step necessary to permit selection or examination of
   the mailbox in a backwards compatible fashion will become more
   difficult to support.  Although it is hoped deployed IMAP servers do
   not advertise UTF8=ONLY for some years, this capability is intended
   to minimize the disruption when legacy support finally goes away.

   The UTF8=ONLY capability implies the UTF8 base capability, the
   UTF8=ALL capability and the UTF8=APPEND capability.  A server that
   advertises UTF8=ONLY need not advertise the three implicit
   capabilities.


8.  Up-Conversion Server Requirements

   When an IMAP4 server uses a traditional mailbox format that includes
   7-bit headers and it chooses to permit access to that mailbox with
   the UTF8 parameter, it MUST support minimal up-conversion as
   described in this section.

   The server MUST support up-conversion of the following address
   header-fields in the message header: From, Sender, To, CC, Bcc,
   Resent-From, Resent-Sender, Resent-To, Resent-CC, Resent-Bcc, and
   Reply-To.  This up-conversion MUST include address local-parts in
   fields downgraded according to [RFC5504], address domains encoded
   according to IDNA [RFC3490], and MIME header encoding [RFC2047] of
   display-names and any [RFC5322] comments.

   The following charsets MUST be supported for up-conversion of MIME
   header encoding [RFC2047]: UTF-8, US-ASCII, ISO-8859-1, ISO-8859-2,
   ISO-8859-3, ISO-8859-4, ISO-8859-5, ISO-8859-6, ISO-8859-7,
   ISO-8859-8, ISO-8859-9, ISO-8859-10, ISO-8859-14, and ISO-8859-15.
   Other widely deployed MIME charsets SHOULD be supported.

   Up-conversion of MIME header encoding of the following headers MUST
   also be implemented: Subject, Date ([RFC5322] comments only),
   Comments, Keywords, Content-Description.

   Server implementations also SHOULD up-convert all MIME body headers
   [RFC2045], SHOULD up-convert or remove the deprecated (and misused)
   "name" parameter [RFC1341] on Content-Type and MUST up-convert the
   Content-Disposition [RFC2183] "filename" parameter, except when any



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   of these are contained within a multipart/signed MIME body part (see
   below).  These parameters can be encoded using the standard MIME
   parameter encoding [RFC2231] mechanism, or via non-standard use of
   MIME header encoding [RFC2047] in quoted strings.

   The IMAP server MUST NOT perform up-conversion of headers and content
   of multipart/signed, as well as Original-Recipient and Return-Path.


9.  Issues with UTF-8 Header Mailstore

   When an IMAP server uses a mailbox format that supports UTF-8 headers
   and it permits selection or examination of that mailbox without the
   UTF8 parameter, it is the responsibility of the server to comply with
   the IMAP4rev1 [RFC3501] base specification and [RFC5322] with respect
   to all header information transmitted over the wire.  Mechanisms for
   7-bit downgrading to help comply with the standards are discussed in
   "Downgrading Mechanism for Email Address Internationalization"
   [RFC5504].

   An IMAP server with a mailbox that supports UTF-8 headers MUST comply
   with the protocol requirements implicit from Section 8.  However, the
   code necessary for such compliance need not be part of the IMAP
   server itself in this case.  For example, the minimal required up-
   conversion could be performed when a message is inserted into the
   IMAP-accessible mailbox.


10.  IANA Considerations

   This adds five new capabilities ("UTF8", "UTF8=USER", "UTF8=APPEND",
   "UTF8=ALL", "UTF8=ONLY") to the IMAP4rev1 capability registry
   [RFC3501].

   This adds two new IMAP4 list selection options and one new IMAP4 list
   return option.

   1.  LIST-EXTENDED option name: UTF8

       LIST-EXTENDED option type: SELECTION

       Implied return options(s): UTF8

       LIST-EXTENDED option description: Causes the LIST response to
       include mailboxes that mandate the UTF8 SELECT/EXAMINE parameter.

       Published specification: RFC XXXX, Section 3.4.1




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       Security considerations: RFC XXXX, Section 11

       Intended usage: COMMON

       Person an email address to contact for further information: see
       Authors' Addresses at the end of this specification

       Owner/Change controller: iesg@ietf.org

   2.  LIST-EXTENDED option name: UTF8ONLY

       LIST-EXTENDED option type: SELECTION

       Implied return options(s): UTF8

       LIST-EXTENDED option description: Causes the LIST response to
       include mailboxes that mandate the UTF8 SELECT/EXAMINE parameter
       and exclude mailboxes that do not support the UTF8 SELECT/EXAMINE
       parameter.

       Published specification: RFC XXXX, Section 3.4.1

       Security considerations: RFC XXXX, Section 11

       Intended usage: COMMON

       Person an email address to contact for further information: see
       Authors' Addresses at the end of this specification

       Owner/Change controller: iesg@ietf.org

   3.  LIST-EXTENDED option name: UTF8

       LIST-EXTENDED option type: RETURN

       Implied return options(s): none

       LIST-EXTENDED option description: Causes the LIST response to
       include \NoUTF8 and \UTF8Only mailbox attributes.

       Published specification: RFC XXXX, Section 3.4.1

       Security considerations: RFC XXXX, Section 11

       Intended usage: COMMON

       Person an email address to contact for further information: see
       Authors' Addresses at the end of this specification



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       Owner/Change controller: iesg@ietf.org


11.  Security Considerations

   The security considerations of UTF-8 [RFC3629] and SASLprep [RFC4013]
   apply to this specification, particularly with respect to use of
   UTF-8 in user names and passwords.  Otherwise, this is not believed
   to alter the security considerations of IMAP4rev1.


12.  References

12.1.  Normative References

   [RFC1341]  Borenstein, N. and N. Freed, "MIME (Multipurpose Internet
              Mail Extensions): Mechanisms for Specifying and Describing
              the Format of Internet Message Bodies", RFC 1341,
              June 1992.

   [RFC2045]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part One: Format of Internet Message
              Bodies", RFC 2045, November 1996.

   [RFC2047]  Moore, K., "MIME (Multipurpose Internet Mail Extensions)
              Part Three: Message Header Extensions for Non-ASCII Text",
              RFC 2047, November 1996.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2183]  Troost, R., Dorner, S., and K. Moore, "Communicating
              Presentation Information in Internet Messages: The
              Content-Disposition Header Field", RFC 2183, August 1997.

   [RFC2231]  Freed, N. and K. Moore, "MIME Parameter Value and Encoded
              Word Extensions:
              Character Sets, Languages, and Continuations", RFC 2231,
              November 1997.

   [RFC3490]  Faltstrom, P., Hoffman, P., and A. Costello,
              "Internationalizing Domain Names in Applications (IDNA)",
              RFC 3490, March 2003.

   [RFC3501]  Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION
              4rev1", RFC 3501, March 2003.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO



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              10646", STD 63, RFC 3629, November 2003.

   [RFC4013]  Zeilenga, K., "SASLprep: Stringprep Profile for User Names
              and Passwords", RFC 4013, February 2005.

   [RFC4466]  Melnikov, A. and C. Daboo, "Collected Extensions to IMAP4
              ABNF", RFC 4466, April 2006.

   [RFC4469]  Resnick, P., "Internet Message Access Protocol (IMAP)
              CATENATE Extension", RFC 4469, April 2006.

   [RFC5161]  Gulbrandsen, A. and A. Melnikov, "The IMAP ENABLE
              Extension", RFC 5161, March 2008.

   [RFC5198]  Klensin, J. and M. Padlipsky, "Unicode Format for Network
              Interchange", RFC 5198, March 2008.

   [RFC5234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234, January 2008.

   [RFC5258]  Leiba, B. and A. Melnikov, "Internet Message Access
              Protocol version 4 - LIST Command Extensions", RFC 5258,
              June 2008.

   [RFC5322]  Resnick, P., Ed., "Internet Message Format", RFC 5322,
              October 2008.

   [RFC5335]  Abel, Y., "Internationalized Email Headers", RFC 5335,
              September 2008.

   [RFC5504]  Fujiwara, K. and Y. Yoneya, "Downgrading Mechanism for
              Email Address Internationalization", RFC 5504, March 2009.

12.2.  Informative References

   [RFC2049]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part Five: Conformance Criteria and
              Examples", RFC 2049, November 1996.

   [RFC2088]  Myers, J., "IMAP4 non-synchronizing literals", RFC 2088,
              January 1997.

   [RFC2277]  Alvestrand, H., "IETF Policy on Character Sets and
              Languages", BCP 18, RFC 2277, January 1998.

   [I-D.ietf-eai-pop]
              Gellens, R. and C. Newman, "POP3 Support for UTF-8",
              draft-ietf-eai-pop-06 (work in progress), June 2009.



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Appendix A.  Design Rationale

   This non-normative section discusses the reasons behind some of the
   design choices in the above specification.

   The basic approach of advertising the ability to access a mailbox in
   UTF-8 mode is intended to permit graceful upgrade, including servers
   that support multiple mailbox formats.  In particular, it would be
   undesirable to force conversion of an entire server mailstore to
   UTF-8 headers, so being able to phase-in support for new mailboxes
   and gradually migrate old mailboxes is permitted by this design.

   UTF8=USER is optional because many identity systems are US-ASCII
   only, so it's helpful to inform the client up-front that UTF-8 won't
   work.

   UTF8=APPEND is optional because it effectively requires IMAP server
   support for down-conversion, which is a much more complex operation
   than up-conversion.

   The UTF8=ONLY mechanism simplifies diagnosis of interoperability
   problems when legacy support goes away.  In the situation where
   backwards compatibility is broken anyway, just-send-UTF-8 IMAP has
   the advantage that it might work with some legacy clients.  However,
   the difficulty of diagnosing interoperability problems caused by a
   just-send-UTF-8 IMAP mechanism is the reason the UTF8=ONLY capability
   mechanism was chosen.

   The up-conversion requirements are designed to balance the desire to
   deprecate and eventually eliminate complicated encodings (like MIME
   header encodings) without creating a significant deployment burden
   for servers.  As IMAP4 servers already require a MIME parser, this
   includes additional server up-conversion requirements not present in
   POP3 Support for UTF-8 [I-D.ietf-eai-pop].

   The set of mandatory charsets comes from two sources: MIME
   requirements [RFC2049] and IETF Policy on Character Sets [RFC2277].
   Including a requirement to up-convert widely deployed encoded
   ideographic charsets to UTF-8 would be reasonable for most scenarios,
   but may require unacceptable table sizes for some embedded devices.
   The open-ended recommendation to support widely deployed charsets
   avoids the political ramifications of attempting to list such
   charsets.  The authors believe market forces, existing open-source
   software, and public conversion tables are sufficient to deploy the
   appropriate charsets.






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Internet-Draft           IMAP Support for UTF-8           September 2009


Appendix B.  Acknowledgments

   TBD.


Authors' Addresses

   Pete Resnick
   Qualcomm Incorporated
   5775 Morehouse Drive
   San Diego, CA  92121-1714
   US

   Phone: +1 858 651 4478
   Email: presnick@qualcomm.com
   URI:   http://www.qualcomm.com/~presnick/


   Chris Newman
   Sun Microsystems
   3401 Centrelake Dr., Suite 410
   Ontario, CA  91761
   US

   Email: chris.newman@sun.com


























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