IMAP Extension for Object Identifiers
RFC 8474
| Document | Type |
RFC - Proposed Standard
(September 2018; No errata)
Updates RFC 3501
|
|
|---|---|---|---|
| Last updated | 2018-09-25 | ||
| Replaces | draft-ietf-extra-imap-uniqueid | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Jiankang Yao | ||
| Shepherd write-up | Show (last changed 2018-06-21) | ||
| IESG | IESG state | RFC 8474 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Alexey Melnikov | ||
| Send notices to | Jiankang Yao <yaojk@cnnic.cn>;aamelnikov@fastmail.fm | ||
| IANA | IANA review state | IANA OK - Actions Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) B. Gondwana, Ed.
Request for Comments: 8474 FastMail
Updates: 3501 September 2018
Category: Standards Track
ISSN: 2070-1721
IMAP Extension for Object Identifiers
Abstract
This document updates RFC 3501 (IMAP4rev1) with persistent
identifiers on mailboxes and messages to allow clients to more
efficiently reuse cached data when resources have changed location on
the server.
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 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8474.
Copyright Notice
Copyright (c) 2018 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
(https://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.
Gondwana Standards Track [Page 1]
RFC 8474 IMAP ObjectID September 2018
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. CAPABILITY Identification . . . . . . . . . . . . . . . . . . 3
4. MAILBOXID Object Identifier . . . . . . . . . . . . . . . . . 3
4.1. New Response Code for CREATE . . . . . . . . . . . . . . 4
4.2. New OK Untagged Response for SELECT and EXAMINE . . . . . 4
4.3. New Attribute for STATUS . . . . . . . . . . . . . . . . 5
5. EMAILID Object Identifier and THREADID Correlator . . . . . . 6
5.1. EMAILID Identifier for Identical Messages . . . . . . . . 6
5.2. THREADID Identifier for Related Messages . . . . . . . . 6
5.3. New Message Data Items in FETCH and UID FETCH Commands . 7
6. New Filters on SEARCH Command . . . . . . . . . . . . . . . . 9
7. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 9
8. Implementation Considerations . . . . . . . . . . . . . . . . 10
8.1. Assigning Object Identifiers . . . . . . . . . . . . . . 10
8.2. Interaction with Special Cases . . . . . . . . . . . . . 11
8.3. Client Usage . . . . . . . . . . . . . . . . . . . . . . 11
8.4. Advice to Client Implementers . . . . . . . . . . . . . . 12
9. Future Considerations . . . . . . . . . . . . . . . . . . . . 12
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
11. Security Considerations . . . . . . . . . . . . . . . . . . . 13
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
12.1. Normative References . . . . . . . . . . . . . . . . . . 13
12.2. Informative References . . . . . . . . . . . . . . . . . 14
Appendix A. Ideas for Implementing Object Identifiers . . . . . 15
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 15
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
IMAP stores are often used by many clients. Each client may cache
data from the server so that it doesn't need to redownload
information. [RFC3501] states that a mailbox can be uniquely
referenced by its name and UIDVALIDITY, and a message within that
mailbox can be uniquely referenced by its mailbox (name +
UIDVALIDITY) and unique identifier (UID). The triple of mailbox
name, UIDVALIDITY, and UID is guaranteed to be immutable.
[RFC4315] defines a COPYUID response that allows a client that copies
messages to know the mapping between the UIDs in the source and
destination mailboxes and, hence, update its local cache.
If a mailbox is successfully renamed by a client, that client will
know that the same messages exist in the destination mailbox name as
previously existed in the source mailbox name.
Gondwana Standards Track [Page 2]
RFC 8474 IMAP ObjectID September 2018
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