Browse Prior Art Database

IMAP4 Login Referrals (RFC2221)

IP.com Disclosure Number: IPCOM000002779D
Original Publication Date: 1997-Oct-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 4 page(s) / 9K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M. Gahrns: AUTHOR

Abstract

When dealing with large amounts of users and many IMAP4 [RFC-2060] servers, it is often necessary to move users from one IMAP4 server to another. For example, hardware failures or organizational changes may dictate such a move.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 32% of the total text.

Network Working Group M. Gahrns

Request for Comments: 2221 Microsoft

Category: Standards Track October 1997

IMAP4 Login Referrals

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 (1997). All Rights Reserved.

1. Abstract

When dealing with large amounts of users and many IMAP4 [RFC-2060]

servers, it is often necessary to move users from one IMAP4 server to

another. For example, hardware failures or organizational changes

may dictate such a move.

Login referrals allow clients to transparently connect to an

alternate IMAP4 server, if their home IMAP4 server has changed.

A referral mechanism can provide efficiencies over the alternative

'proxy method', in which the local IMAP4 server contacts the remote

server on behalf of the client, and then transfers the data from the

remote server to itself, and then on to the client. The referral

mechanism's direct client connection to the remote server is often a

more efficient use of bandwidth, and does not require the local

server to impersonate the client when authenticating to the remote

server.

2. Conventions used in this document

In examples, "C:" and "S:" indicate lines sent by the client and

server respectively.

A home server, is an IMAP4 server that contains the user's inbox.

A remote server is a server that contains remote mailboxes.

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

"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this

document are to be interpreted as described in [RFC-2119].

3. Introduction and Overview

IMAP4 servers that support this extension MUST list the keyword

LOGIN-REFERRALS in their CAPABILITY response. No client action is

needed to invoke the LOGIN-REFERRALS capability in a server.

A LOGIN-REFERRALS capable IMAP4 server SHOULD NOT return a referral

to a server that will return a referral. A client MUST NOT follow

more than 10 levels of referral without consulting the user.

A LOGIN-REFERRALS response code MUST contain as an argument a valid

IMAP server URL as defined in [IMAP-URL].

A home server referral consists of either a tagged NO or OK, or...