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Internet Message Access Protocol (IMAP) - MULTIAPPEND Extension (RFC3502)

IP.com Disclosure Number: IPCOM000011811D
Original Publication Date: 2003-Mar-01
Included in the Prior Art Database: 2003-Mar-18
Document File: 8 page(s) / 13K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M. Crispin: AUTHOR

Abstract

This document describes the multiappending extension to the Internet Message Access Protocol (IMAP) (RFC 3501). This extension provides substantial performance improvements for IMAP clients which upload multiple messages at a time to a mailbox on the server.

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Network Working Group� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � M. Crispin

Request for Comments: 3502� � � � � � � � � � � � � � � � � � � � � University of Washington

Category: Standards Track� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � March 2003

� � � Internet Message Access Protocol (IMAP) - MULTIAPPEND Extension

Status of this Memo

� � This document specifies an Internet standards track protocol for the

� � Internet community, and requests discussion and suggestions for

� � improvements.� Please refer to the current edition of the "Internet

� � Official Protocol Standards" (STD 1) for the standardization state

� � and status of this protocol.� Distribution of this memo is unlimited.

Copyright Notice

� � Copyright (C) The Internet Society (2003).� All Rights Reserved.

Abstract

� � This document describes the multiappending extension to the Internet

� � Message Access Protocol (IMAP) (RFC 3501).� This extension provides

� � substantial performance improvements for IMAP clients which upload

� � multiple messages at a time to a mailbox on the server.

� � A server which supports this extension indicates this with a

� � capability name of "MULTIAPPEND".

Terminology

� � The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

� � "SHOULD", "SHOULD NOT", "MAY", and "OPTIONAL" in this document are to

� � be interpreted as described in [KEYWORDS].

Introduction

� � The MULTIAPPEND extension permits uploading of multiple messages with

� � a single command.� When used in conjunction with the [LITERAL+]

� � extension, the entire upload is accomplished in a single

� � command/response round trip.

� � A MULTIAPPEND APPEND operation is atomic; either all messages are

� � successfully appended, or no messages are appended.

� � In the base IMAP specification, each message must be appended in a

� � separate command, and there is no mechanism to "unappend" messages if

� � an error occurs while appending.� Also, some mail stores may require

Crispin� � � � � � � � � � � � � � � � � � � � Standards Track� � � � � � � � � � � � � � � � � � � � [Page 1]

RFC 3502� � � � � � � � � � � � � � � � � � � IMAP MULTIAPPEND� � � � � � � � � � � � � � � � � March 2003

� � an expensive "open/lock + sync/unlock/close" operation as part of

� � appending; this can be quite expensive if it must be done on a

� � per-message basis.

� � If the server supports both LITERAL+ and pipelining but not

� � MULTIAPPEND, it may be possible to get some of the performance

� � advantages of MULTIAPPEND by doing a pipelined "batch" append.

� � However, it will not work as well as MULTIAPPEND for the following

� � reasons:

� � � � � � � 1) Multiple APPEND commands, even as part of a pipelined batch,

� � � � � � � are non-atomic by definition.� There is no way to revert the

� � � � � � � mailbox to the state before the batch append in the event of an

� � � � � � � error.

� � � � � � � 2) It may not be feasible for the ser...