IMAP Support for UTF-8
RFC 6855
Document | Type |
RFC - Proposed Standard
(March 2013; Errata)
Obsoletes RFC 5738
Was draft-ietf-eai-5738bis (eai WG)
|
|
---|---|---|---|
Authors | Pete Resnick , Chris Newman , Sean Shen | ||
Last updated | 2020-01-21 | ||
Replaces | draft-ietf-eai-5378bis | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized with errata bibtex | ||
Reviews | |||
Stream | WG state | WG Document | |
Document shepherd | John Klensin | ||
Shepherd write-up | Show (last changed 2012-08-24) | ||
IESG | IESG state | RFC 6855 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Barry Leiba | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) P. Resnick, Ed. Request for Comments: 6855 Qualcomm Incorporated Obsoletes: 5738 C. Newman, Ed. Category: Standards Track Oracle ISSN: 2070-1721 S. Shen, Ed. CNNIC March 2013 IMAP Support for UTF-8 Abstract This specification extends the Internet Message Access Protocol (IMAP) to support UTF-8 encoded international characters in user names, mail addresses, and message headers. This specification replaces RFC 5738. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6855. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Resnick, et al. Standards Track [Page 1] RFC 6855 IMAP Support for UTF-8 March 2013 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions Used in This Document . . . . . . . . . . . . . . 2 3. "UTF8=ACCEPT" IMAP Capability and UTF-8 in IMAP Quoted-Strings . . . . . . . . . . . . . . . . . . . . . . . . 3 4. IMAP UTF8 "APPEND" Data Extension . . . . . . . . . . . . . . 4 5. "LOGIN" Command and UTF-8 . . . . . . . . . . . . . . . . . . 5 6. "UTF8=ONLY" Capability . . . . . . . . . . . . . . . . . . . . 5 7. Dealing with Legacy Clients . . . . . . . . . . . . . . . . . 6 8. Issues with UTF-8 Header Mailstore . . . . . . . . . . . . . . 7 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 10. Security Considerations . . . . . . . . . . . . . . . . . . . 8 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 11.1. Normative References . . . . . . . . . . . . . . . . . . 9 11.2. Informative References . . . . . . . . . . . . . . . . . 10 Appendix A. Design Rationale . . . . . . . . . . . . . . . . . . 11 Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . . 11 1. Introduction This specification forms part of the Email Address Internationalization protocols described in the Email Address Internationalization Framework document [RFC6530]. It extends IMAP [RFC3501] to permit UTF-8 [RFC3629] in headers, as described in "Internationalized Email Headers" [RFC6532]. It also adds a mechanism to support mailbox names using the UTF-8 charset. This specification creates two new IMAP capabilities to allow servers to advertise these new extensions. This specification assumes that the IMAP server will be operating in a fully internationalized environment, i.e., one in which all clients accessing the server will be able to accept non-ASCII message header fields and other information, as specified in Section 3. At least during a transition period, that assumption will not be realistic for many environments; the issues involved are discussed in Section 7 below. This specification replaces an earlier, experimental approach to the same problem [RFC5738]. 2. 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]. Resnick, et al. Standards Track [Page 2] RFC 6855 IMAP Support for UTF-8 March 2013 The formal syntax uses the Augmented Backus-Naur Form (ABNF) [RFC5234] notation. In addition, rules from IMAP [RFC3501], UTF-8 [RFC3629], Extensions to IMAP ABNF [RFC4466], and IMAP "LIST" commandShow full document text