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Internet Engineering Task Force (IETF) R. Sparks Request for Comments: 7017 Oracle 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.

 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://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.

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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.)

Sparks Informational [Page 2] RFC 7017 IMAP Access to IETF Email List Archives August 2013

 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.

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 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.

Sparks Informational [Page 4] RFC 7017 IMAP Access to IETF Email List Archives August 2013

 [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
 Oracle
 17210 Campbell Road
 Suite 250
 Dallas, Texas  75254-4203
 USA

 EMail: rjsparks@nostrum.com

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