IMAP REPLACE Extension
RFC 8508
Internet Engineering Task Force (IETF) S. Brandt
Request for Comments: 8508 Verizon
Category: Standards Track January 2019
ISSN: 2070-1721
IMAP REPLACE Extension
Abstract
This document defines an IMAP extension that can be used to replace
an existing message in a message store with a new message. Message
replacement is a common operation for clients that automatically save
drafts or notes as a user composes them.
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/rfc8508.
Copyright Notice
Copyright (c) 2019 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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RFC 8508 IMAP REPLACE Extension January 2019
Table of Contents
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. REPLACE and UID REPLACE . . . . . . . . . . . . . . . . . . . 3
3.1. Advertising Support for REPLACE . . . . . . . . . . . . . 3
3.2. REPLACE Command . . . . . . . . . . . . . . . . . . . . . 3
3.3. UID REPLACE Command . . . . . . . . . . . . . . . . . . . 4
3.4. Semantics of REPLACE and UID REPLACE . . . . . . . . . . 5
3.5. IMAP State Diagram Impacts . . . . . . . . . . . . . . . 6
4. Interaction with Other Extensions . . . . . . . . . . . . . . 6
4.1. ACL . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2. CATENATE . . . . . . . . . . . . . . . . . . . . . . . . 6
4.3. UIDPLUS . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.4. IMAP Events in Sieve . . . . . . . . . . . . . . . . . . 8
4.5. CONDSTORE/QRESYNC . . . . . . . . . . . . . . . . . . . . 8
4.6. OBJECTID . . . . . . . . . . . . . . . . . . . . . . . . 8
4.7. MULTIAPPEND . . . . . . . . . . . . . . . . . . . . . . . 8
5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 11
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 11
1. Overview
This document defines an IMAP ([RFC3501]) extension to facilitate the
replacement of an existing message with a new one. This is
accomplished by defining a new REPLACE command and extending the
Unique Identifier (UID) command to allow UID REPLACE.
Since there is no replace function in the base IMAP specification,
clients have instead had to use a combination of three separate
commands issued in serial fashion; APPEND, STORE, and EXPUNGE.
Pipelining of these three commands is not recommended since failure
of any individual command should prevent subsequent commands from
being executed lest the original message version be lost.
Because of the non-atomic nature of the existing sequence,
interruptions can leave messages in intermediate states that can be
seen and acted upon by other clients. Such interruptions can also
strand older revisions of messages, thereby forcing the user to
manually clean up multiple revisions of the same message in order to
avoid wasteful quota consumption. Additionally, the existing
sequence can fail on APPEND due to an over-quota condition even
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