Internet Draft K. Murchison Document: draft-murchison-sieve-subaddress-06.txt Oceana Matrix Ltd. Expires October 4, 2003 30 March 2003 Sieve -- Subaddress Extension Status of this Memo This document is an Internet-Draft and is subject to all provisions of Section 10 of RFC2026. 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright Notice Copyright (C) The Internet Society 2003. All Rights Reserved. Abstract On email systems that allow for "subaddressing" or "detailed addressing" (eg, "ken+sieve@example.org"), it is sometimes desirable to make comparisons against these sub-parts of addresses. This draft defines an extension to the Sieve mail filtering language that allows users to compare against the user and detail parts of an address. Expires October 4, 2003 Murchison [Page 1] Internet Draft Sieve -- Subaddress Extension March 30, 2003 Table of Contents Status of this Memo . . . . . . . . . . . . . . . . . . . . . . . . 1 Copyright Notice . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0. Meta-information on this draft . . . . . . . . . . . . . . . 3 0.1. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 3 0.2. Change History . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Capability Identifier . . . . . . . . . . . . . . . . . . . . 4 3. Subaddress Comparisons . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. Normative References . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 8. Author's Address . . . . . . . . . . . . . . . . . . . . . . 7 9. Intellectual Property Considerations . . . . . . . . . . . . 7 10. Full Copyright Statement . . . . . . . . . . . . . . . . . . 8 Expires October 4, 2003 Murchison [Page 2] Internet Draft Sieve -- Subaddress Extension March 30, 2003 0. Meta-information on this draft This information is intended to facilitate discussion. It will be removed when this document leaves the Internet-Draft stage. 0.1. Discussion This draft is intended to be an extension to the Sieve mail filtering language, available from the RFC repository as . This draft and the Sieve language itself are being discussed on the MTA Filters mailing list at . Subscription requests can be sent to (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 . 0.2. Change History Since -05: Add IANA considerations, conform to ID Nits. 1. Introduction Subaddressing is the practice of appending some "detail" information to the local-part of an [IMAIL] address to indicate that the message should be delivered to the set of messages 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: - A message addressed to "ken+sieve@example.org" is delivered into a mailbox called "sieve" belonging to the user "ken". - A message addressed to "5551212#123@example.org" is delivered to the voice mailbox number "123" at phone number "5551212". Expires October 4, 2003 Murchison [Page 3] Internet Draft Sieve -- Subaddress Extension March 30, 2003 This document describes an extension to the Sieve language defined by [SIEVE] for comparing against the "user" and "detail" sub-parts of an address. Conventions for notations are as in [SIEVE] section 1.1, including use of [KEYWORDS]. 2. Capability Identifier The capability string associated with the extension defined in this document is "subaddress". 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 prefered 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 (eg, "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 (eg, "sieve" in "ken+sieve@example.org"). If no separator characater exists, the 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. 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. Expires October 4, 2003 Murchison [Page 4] Internet Draft Sieve -- Subaddress Extension March 30, 2003 The ":user" and ":detail" address parts are subject to the same rules and restrictions as the standard address parts defined in [SIEVE]. For convenience, the "ADDRESS-PART" syntax element defined in [SIEVE] is augmented here as follows: ADDRESS-PART =/ ":user" / ":detail" 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", "cc", "bcc"] "foo" { redirect "ken@example.edu"; } 4. Security Considerations Security considerations are discussed in [SIEVE]. It is believed that this extension does not introduce any additional security concerns. Expires October 4, 2003 Murchison [Page 5] Internet Draft Sieve -- Subaddress Extension March 30, 2003 5. IANA Considerations The following template specifies the IANA registration of the Sieve extension specified in this document: To: iana@iana.org Subject: Registration of new Sieve extension Capability name: subaddress Capability keyword: subaddress Capability arguments: N/A Standards Track/IESG-approved experimental RFC number: this RFC Person and email address to contact for further information: Kenneth Murchison ken@oceana.com This information should be added to the list of sieve extensions given on http://www.iana.org/assignments/sieve-extensions. 6. Normative References [IMAIL] Resnick, P., Ed., "Internet Message Format", QUALCOMM Incorporated, RFC 2822, April 2001. [KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", Harvard University, RFC 2119, March 1997. [SIEVE] Showalter, T., "Sieve: A Mail Filtering Language", Mira¡ point, Inc., RFC 3028, January 2001. 7. Acknowledgments Thanks to Tim Showalter, Alexey Melnikov, Michael Salmon, Randall Gellens, Philip Guenther and Jutta Degener for their help with this document. Expires October 4, 2003 Murchison [Page 6] Internet Draft Sieve -- Subaddress Extension March 30, 2003 8. Author's Address Kenneth Murchison Oceana Matrix Ltd. 21 Princeton Place Orchard Park, NY 14127 EMail: ken@oceana.com 9. Intellectual Property Considerations The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Expires October 4, 2003 Murchison [Page 7] Internet Draft Sieve -- Subaddress Extension March 30, 2003 10. Full Copyright Statement Copyright (C) The Internet Society 2003. All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. 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