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Internet Engineering Task Force (IETF)                         R. SparksRequest for Comments: 7017                                        OracleCategory: Informational                                      August 2013ISSN: 2070-1721IMAP Access to IETF Email List ArchivesAbstract   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; seeSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://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 toBCP 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.Sparks                        Informational                     [Page 1]

RFC 7017         IMAP Access to IETF Email List Archives     August 2013Table of Contents1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .22.  Requirements for IMAP Access to Archived IETF Lists . . . . .23.  Internationalized Address Considerations  . . . . . . . . . .34.  Security Considerations . . . . . . . . . . . . . . . . . . .35.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .46.  Informative References  . . . . . . . . . . . . . . . . . . .41.  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.Sparks                        Informational                     [Page 3]

RFC 7017         IMAP Access to IETF Email List Archives     August 2013   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",RFC6203, 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",RFC6778, 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.comSparks                        Informational                     [Page 5]