Sieve Working Group K. Murchison Internet-Draft Oceana Matrix Ltd. Obsoletes: 3598 (if approved) February 7, 2005 Expires: August 11, 2005 Sieve Email Filtering -- Subaddress Extension draft-ietf-sieve-rfc3598bis-00.txt Status of this Memo This document is an Internet-Draft and is subject to all provisions of Section 3 of RFC 3667. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 11, 2005. Copyright Notice Copyright (C) The Internet Society (2005). Abstract On email systems that allow for "subaddressing" or "detailed addressing" (e.g., "ken+sieve@example.org"), it is sometimes desirable to make comparisons against these sub-parts of addresses. This document defines an extension to the Sieve mail filtering language that allows users to compare against the user and detail parts of an address. Murchison Expires August 11, 2005 [Page 1]
Internet-Draft Sieve -- Subaddress Extension February 2005 Meta-information on this document This information is intended to facilitate discussion. It will be removed when this document leaves the Internet-Draft stage. This document is intended to be an update to the existing "subaddress" extension to the Sieve mail filtering language, available from the RFC repository as <ftp://ftp.isi.edu/in-notes/rfc3598.txt> and <ftp://ftp.isi.edu/in-notes/rfc3028.txt> respectively. This document and the Sieve language itself are being discussed on the MTA Filters mailing list at <mailto:ietf-mta-filters@imc.org>. Subscription requests can be sent to <mailto:ietf-mta-filters-request@imc.org?body=subscribe> (send an email message with the word "subscribe" in the body). More information on the mailing list along with a WWW archive of back messages is available at <http://www.imc.org/ietf-mta-filters/>. Murchison Expires August 11, 2005 [Page 2]
Internet-Draft Sieve -- Subaddress Extension February 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Capability Identifier . . . . . . . . . . . . . . . . . . . 5 3. Subaddress Comparisons . . . . . . . . . . . . . . . . . . . 6 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . 9 6. Normative References . . . . . . . . . . . . . . . . . . . . 9 Author's Address . . . . . . . . . . . . . . . . . . . . . . 9 A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 10 B. Changes since RFC3598 . . . . . . . . . . . . . . . . . . . 11 Intellectual Property and Copyright Statements . . . . . . . 12 Murchison Expires August 11, 2005 [Page 3]
Internet-Draft Sieve -- Subaddress Extension February 2005 1. Introduction Subaddressing is the practice of appending some "detail" information to the local-part of an [RFC2822] address to indicate that the message should be delivered to the mailbox specified by the "detail" information. The "detail" information is prefixed with a special "separator character" (typically "+") which forms the boundary between the "user" (original local-part) and the "detail" sub-parts of the address, much like the "@" character forms the boundary between the local-part and domain. Typical uses of subaddressing might be: o A message addressed to "ken+sieve@example.org" is delivered into a mailbox called "sieve" belonging to the user "ken". o A message addressed to "5551212#123@example.org" is delivered to the voice mailbox number "123" at phone number "5551212". This document describes an extension to the Sieve language defined by [RFC3028] for comparing against the "user" and "detail" sub-parts of an address. Conventions for notations are as in [RFC3028] section 1.1, including use of [RFC2119]. Murchison Expires August 11, 2005 [Page 4]
Internet-Draft Sieve -- Subaddress Extension February 2005 2. Capability Identifier The capability string associated with the extension defined in this document is "subaddress". Murchison Expires August 11, 2005 [Page 5]
Internet-Draft Sieve -- Subaddress Extension February 2005 3. Subaddress Comparisons Commands that act exclusively on addresses may take the optional tagged arguments ":user" and ":detail" to specify what sub-part of the local-part of the address will be acted upon. NOTE: In most cases, the envelope "to" address is the preferred address to examine for subaddress information when the desire is to sort messages based on how they were addressed so as to get to a specific recipient. The envelope address is, after all, the reason a given message is being processed by a given sieve script for a given user. This is particularly true when mailing lists, aliases, and "virtual domains" are involved since the envelope may be the only source of detail information for the specific recipient. The ":user" argument specifies that sub-part of the local-part which lies to the left of the separator character (e.g., "ken" in "ken+sieve@example.org"). If no separator character exists, then ":user" specifies the entire left-side of the address (equivalent to ":localpart"). The ":detail" argument specifies that sub-part of the local-part which lies to the right of the separator character (e.g., "sieve" in "ken+sieve@example.org"). If no separator character exists, the test evaluates to false. If nothing lies to the right of the separator character, then ":detail" ":is" the null key (""). Otherwise, the ":detail" sub-part contains the null key. NOTE: If the separator character occurs more than once in the local-part, then the address MUST be split at the left-most separator. Implementations MUST make sure that the separator character matches that which is used and/or allowed by the encompassing mail system, otherwise unexpected results might occur. Implementations SHOULD allow the separator character to be configurable so that they may be used with a variety of mail systems. Note that the mechanisms used to define and/or query the separator character used by the mail system are outside the scope of this document. The ":user" and ":detail" address parts are subject to the same rules and restrictions as the standard address parts defined in [RFC3028]. For convenience, the "ADDRESS-PART" syntax element defined in [RFC3028] is augmented here as follows: ADDRESS-PART =/ ":user" / ":detail" Murchison Expires August 11, 2005 [Page 6]
Internet-Draft Sieve -- Subaddress Extension February 2005 A diagram showing the ADDRESS-PARTs of a email address utilizing a separator character of '+' is shown below: :user "+" :detail "@" :domain `-----------------' :local-part Example: require "subaddress"; # File mailing list messages (subscribed as "ken+mta-filters"). if envelope :detail "to" "mta-filters" { fileinto "inbox.ietf-mta-filters"; } # If a message is not to me (ignoring +detail), junk it. if not allof (address :user ["to", "cc", "bcc"] "ken", address :domain ["to", "cc", "bcc"] "example.org") { discard; # Redirect all mail sent to +foo. if envelope :detail "to" "foo" { redirect "ken@example.edu"; } Murchison Expires August 11, 2005 [Page 7]
Internet-Draft Sieve -- Subaddress Extension February 2005 4. IANA Considerations This document requests that the IANA update the entry for the "subaddress" Sieve extension to point at this document. Murchison Expires August 11, 2005 [Page 8]
Internet-Draft Sieve -- Subaddress Extension February 2005 5. Security Considerations Security considerations are discussed in [RFC3028]. It is believed that this extension does not introduce any additional security concerns. 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2822] Resnick, P., "Internet Message Format", RFC 2822, April 2001. [RFC3028] Showalter, T., "Sieve: A Mail Filtering Language", RFC 3028, January 2001. Author's Address Kenneth Murchison Oceana Matrix Ltd. 21 Princeton Place Orchard Park, NY 14127 US Phone: +1 716 662 8973 Email: ken@oceana.com Murchison Expires August 11, 2005 [Page 9]
Internet-Draft Sieve -- Subaddress Extension February 2005 Appendix A. Acknowledgments Thanks to Tim Showalter, Alexey Melnikov, Michael Salmon, Randall Gellens, Philip Guenther and Jutta Degener for their help with this document. Murchison Expires August 11, 2005 [Page 10]
Internet-Draft Sieve -- Subaddress Extension February 2005 Appendix B. Changes since RFC3598 o Added note regarding processing of local-part with multiple separator characters. o Fixed envelope test example to only use "to" address. Murchison Expires August 11, 2005 [Page 11]
Internet-Draft Sieve -- Subaddress Extension February 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Murchison Expires August 11, 2005 [Page 12]
