Internet Engineering Task Force (IETF) R. Sparks
Request for Comments: 7017 Tekelec
Category: Informational August 2013
ISSN: 2070-1721
IMAP Access to IETF Email List Archives
Abstract
The IETF makes heavy use of email lists to conduct its work. This
often involves accessing the archived history of those email lists.
Participants would like to have the ability to browse and search
those archives using standard IMAP clients. This memo captures the
requirements for providing a service that would allow such browsing
and searching, and it is intended as input to a later activity for
the design and development of such a service.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
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). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see 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/rfc7017.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements for IMAP Access to Archived IETF Lists . . . . . 2
3. Internationalized Address Considerations . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
6. Informative References . . . . . . . . . . . . . . . . . . . 4
1. Introduction
The IETF makes heavy use of email lists to conduct its work. This
often involves accessing the archived history of those email lists.
Requirements for improved web-based browsing and searching of these
archives are captured in [RFC6778]. Participants would like to have
the ability to browse and search those archives using standard IMAP
clients. This memo captures the requirements for providing a service
that would allow such browsing and searching, and it is intended as
input to a later activity for the design and development of such a
service.
2. Requirements for IMAP Access to Archived IETF Lists
Many participants would prefer to access the list archives using IMAP
[RFC3501]. Providing this access while meeting the following
requirements will likely require an IMAP server with specialized
capabilities.
o The system should expose the archive using an IMAP interface, with
each list represented as a mailbox.
o This interface must work with standard IMAP clients.
o The interface should allow users that have provided credentials to
each have their own read/unread marks for messages. Allowing
other annotation is desirable. The implementation should consider
taking advantage of the IMAP extensions for ANNOTATE [RFC5257] and
METADATA [RFC5464].
o It must be possible for administrators to set per-user storage
quotas, limiting the space a user can consume with annotations.
o The interface must not allow users to modify the underlying
message or metadata other than the read/unread marks and
annotations described above. Specifically, users must not be able
to delete or insert messages, or move them between mailboxes in
the archive. (Clients will, of course, be able to make local
copies of messages from the archive.)
o The interface must have server-side searching enabled and should
scale to support multiple simultaneous extensive searches. The
server should provide the enhanced search capabilities described
in [RFC6778]. The implementation should consider taking advantage
of the extensions defined for IMAP SORT and THREAD [RFC5256],
multimailbox search [RFC6237], and fuzzy search [RFC6203].
o When the system requires credentials, it must use the
datatracker's authentication system.
- While the vast majority of archived lists have an open
access policy, some archived lists have restricted archives.
The system must make it possible to limit access to a
restricted archive based on login credentials.
- The system must allow access to open archives with or
without providing credentials. Specifically, the system
will allow anonymous access using the Simple Authentication
and Security Layer (SASL) ANONYMOUS mechanism [RFC4505] or a
LOGIN command with a special username (such as "anonymous")
determined by the administrator.
3. Internationalized Address Considerations
The implementation should anticipate internationalized email
addresses as discussed in the following three documents: [RFC6532],
[RFC6531], and [RFC6855]. There is no firm requirement at this time.
4. Security Considerations
Allowing IMAP as an interface for browsing and searching the archives
of IETF email lists does not affect the security of the Internet in
any significant fashion.
Searching can be input/output (I/O) and CPU intensive. Clients that
make local copies of all messages in a mailbox can also present an I/
O burden, particularly when synchronizing for the first time. The
implementors of this interface should consider the potential for
maliciously crafted searches attempting to consume a damaging amount
of resources. The implementors should consider the potential for
denial-of-service attacks through making many connections to the
interface. The implementors should consider ways to rate limit I/O
due to making local copies of messages.
Storing read/unread marks and other annotations requires potentially
unbounded storage space. The implementors of this interface should
consider the potential for maliciously crafted annotations attempting
to consume a damaging amount of storage space. The implementors
should consider making it easy to alert the administrator when a user
begins consuming exceptional amounts of space.
5. Acknowledgements
This text was derived directly from an early version of the document
that became [RFC6778], which incorporated text suggestions from
Alexey Melnikov, Pete Resnick, and S. Moonesamy. Barry Leiba
suggested several references to IMAP extensions for an implementation
to consider. Reviews were provided by Martin Duerst, Carl Wallace,
Wassim Haddad, and Juergen Schoenwaelder.
6. Informative References
[RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION
4rev1", RFC 3501, March 2003.
[RFC4505] Zeilenga, K., "Anonymous Simple Authentication and
Security Layer (SASL) Mechanism", RFC 4505, June 2006.
[RFC5256] Crispin, M. and K. Murchison, "Internet Message Access
Protocol - SORT and THREAD Extensions", RFC 5256, June
2008.
[RFC5257] Daboo, C. and R. Gellens, "Internet Message Access
Protocol - ANNOTATE Extension", RFC 5257, June 2008.
[RFC5464] Daboo, C., "The IMAP METADATA Extension", RFC 5464,
February 2009.
[RFC6203] Sirainen, T., "IMAP4 Extension for Fuzzy Search", RFC
6203, March 2011.
[RFC6237] Leiba, B. and A. Melnikov, "IMAP4 Multimailbox SEARCH
Extension", RFC 6237, May 2011.
[RFC6531] Yao, J. and W. Mao, "SMTP Extension for Internationalized
Email", RFC 6531, February 2012.
[RFC6532] Yang, A., Steele, S., and N. Freed, "Internationalized
Email Headers", RFC 6532, February 2012.
[RFC6778] Sparks, R., "Requirements for Archiving IETF Email Lists
and for Providing Web-Based Browsing and Searching", RFC
6778, October 2012.
[RFC6855] Resnick, P., Newman, C., and S. Shen, "IMAP Support for
UTF-8", RFC 6855, March 2013.
Author's Address
Robert Sparks
Tekelec
17210 Campbell Road
Suite 250
Dallas, Texas 75254-4203
USA
EMail: rjsparks@nostrum.com