Network Working Group Ken Murchison Document: draft-murchison-sieve-subaddress-02.txt Oceana Matrix Ltd. Expires March 26, 2001 21 September 2000 Sieve -- Subaddress Extension Status of this Memo This document is an Internet-Draft and is in full conformance with 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/ietf/1id-abstracts.txt To view the list Internet-Draft Shadow Directories, see http://www.ietf.org/shadow.html. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society 2000. 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 March 26, 2001 Murchison [Page 1] Internet Draft Sieve -- Subaddress Extension September 21, 2000 TTaabbllee ooff CCoonntteennttss Status of this Memo . . . . . . . . . . . . . . . . . . . . . . . . 1 Copyright Notice . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0. Meta-information on this draft . . . . . . . . . . . . . . . 3 0.1. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 3 0.2. Known Issues . . . . . . . . . . . . . . . . . . . . . . . . 3 0.3. Noted Changes . . . . . . . . . . . . . . . . . . . . . . . . 3 0.3.1 since -01 . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0.3.2 since -00 . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Capability Identifier . . . . . . . . . . . . . . . . . . . . 4 3. Subaddress Comparisons . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 6. Author's Address . . . . . . . . . . . . . . . . . . . . . . 6 Appendix A. References . . . . . . . . . . . . . . . . . . . . . . 6 Appendix B. Full Copyright Statement . . . . . . . . . . . . . . . 7 Expires March 26, 2001 Murchison [Page 2] Internet Draft Sieve -- Subaddress Extension September 21, 2000 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 Internet-Drafts repository as (where 12 is the version number, which is actually currently 12). 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. Known Issues The names of the capability identifier and address sub-parts are still being debated. Suggestions for the capability identifier are: "detailed-address", "detail-addressing" and "userdetail". Suggestions for the address sub-parts are: ":cabinet" / ":folder" and ":base" / ":detail". 0.3. Noted Changes 0.3.1 since -01 Added description of subaddressing inspired by Randy Gellens. Added discussion of handling different separator characters. Editorial changes. Expires March 26, 2001 Murchison [Page 3] Internet Draft Sieve -- Subaddress Extension September 21, 2000 0.3.2 since -00 Added augmented ADDRESS-PART syntax element. Editorial changes. 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". 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. Expires March 26, 2001 Murchison [Page 4] Internet Draft Sieve -- Subaddress Extension September 21, 2000 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, or nothing lies to the right of the separator character, then ":detail" ":is" the null key (""). Implementations SHOULD allow the separator character to be configurable to match that which is used by the email system. 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"; # 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 +school. if address :detail ["to", "cc", "bcc"] "foo" { redirect "ken@example.edu"; } Expires March 26, 2001 Murchison [Page 5] Internet Draft Sieve -- Subaddress Extension September 21, 2000 4. Security Considerations Security considerations are discussed in [SIEVE]. It is believed that this extension doesn't introduce any additional security concerns. 5. Acknowledgments Thanks to Tim Showalter, Alexey Melnikov, Michael Salmon and Randall Gellens for their help with this document. 6. Author's Address Ken Murchison Oceana Matrix Ltd. 21 Princeton Place Orchard Park, NY 14127 Phone: (716) 662-8973 EMail: ken@oceana.com Appendix A. References [IMAIL] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", University of Delaware, RFC 822, August 1982. [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., Work In Progress. Expires March 26, 2001 Murchison [Page 6] Internet Draft Sieve -- Subaddress Extension September 21, 2000 Appendix B. Full Copyright Statement Copyright (C) The Internet Society 2000. 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 implementation 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 develop- ing 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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