Sieve Working Group B. Leiba Internet-Draft IBM T.J. Watson Research Center Expires: June 10, 2006 M. Haardt freenet.de AG December 7, 2005 Sieve Notification Mechanism: mailto draft-ietf-sieve-notify-mailto-00 Status of this Memo 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 becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 June 10, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document describes a profile of the Sieve extension for notifications, to allow notifications to be sent by electronic mail. Leiba & Haardt Expires June 10, 2006 [Page 1] Internet-Draft Sieve Notification Mechanism: mailto December 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Conventions used in this document . . . . . . . . . . . . . . 3 2. Definition . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1 Notify tag ":method" . . . . . . . . . . . . . . . . . . . . . 4 2.2 Notify tag ":id" . . . . . . . . . . . . . . . . . . . . . . . 4 2.3 Notify tag ":priority" . . . . . . . . . . . . . . . . . . . . 4 2.4 Notify tag ":message" . . . . . . . . . . . . . . . . . . . . 4 2.5 Other Definitions . . . . . . . . . . . . . . . . . . . . . . 5 3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Internationalization Considerations . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.1 Normative References . . . . . . . . . . . . . . . . . . . . . 11 7.2 Non-Normative References . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 11 Intellectual Property and Copyright Statements . . . . . . . . 13 Leiba & Haardt Expires June 10, 2006 [Page 2] Internet-Draft Sieve Notification Mechanism: mailto December 2005 1. Introduction 1.1 Overview The [Notify] extension to the [Sieve] mail filtering language is a framework for providing notifications by employing URIs to specify the notification mechanism. This document defines how [mailto] URIs are used to generate notifications by e-mail. 1.2 Conventions used in this document Conventions for notations are as in [Sieve] section 1.1, including the use of [Kwds] and the use of [ABNF]. [[no abnf ref: We don't actually need the ABNF reference...]] The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [Kwds]. Leiba & Haardt Expires June 10, 2006 [Page 3] Internet-Draft Sieve Notification Mechanism: mailto December 2005 2. Definition The mailto mechanism results in the sending of a new email message (a "notification message") to notify a recipient about a "triggering message". 2.1 Notify tag ":method" The mailto notification mechanism uses standard mailto URIs as specified in [mailto]. URI parameters with hname "from", "subject" and "received" are ignored if specified; all other parameters are accepted. [[Barry ignored: Should we ignore them, or should their presence be an error?]] 2.2 Notify tag ":id" The :id tag has no special meaning for this notification mechanism, and this specification puts no restriction on its use. 2.3 Notify tag ":priority" The :priority tag has no special meaning for this notification mechanism, and this specification puts no restriction on its use. Implementations MAY use the value of :priority to set a priority or importance indication on the notification message. 2.4 Notify tag ":message" o The "From:" header field and the envelope sender of the notification message are set to the envelope "to" field from the triggering message, as used by Sieve. [[Barry from: It might be better in some cases for the notification to "come from" the sender of the triggering message. In other cases it might be better for all notifications to come from the "mail system". I think we should define a way to specify the behaviour here, perhaps with a new notify tag.]] [[Barry sender: Should we also provide a mapping or setting for the "Sender:" header field?]] o The "To:" header field and the envelope recipient(s) of the notification message are set to the address(es) specified in URI (including any URI parameters where the hname is "to"). [[Barry to: I'd like some way to specify that the To: header Leiba & Haardt Expires June 10, 2006 [Page 4] Internet-Draft Sieve Notification Mechanism: mailto December 2005 should be retained from the triggering message. In fact, I'd like a way to say that ALL headers be retained.]] o The "Received:" headers from the triggering message are retained in the notification message, as these may help detect and prevent mail loops. o The "Subject:" header of the notification message contains the value defined by the :message notify tag, as described in [Notify]. If there is no :message tag, the subject is retained from the triggering message. Note that Sieve variables can be used to advantage here, as shown in the example in Section 3. o All other header fields of the notification message either are as specified in the URI, or have implementation-specific values; their values are not defined here. o If the mailto URI contains a "body" parameter, the value of that parameter is used as the body of the notification message. If there is no "body" parameter, the body of the notification message is empty. [[Barry body: I'd like some way to specify that the body contain the body of the triggering message.]] 2.5 Other Definitions Because the receipt of an email message is generating another email message, implementations MUST take steps to avoid mail loops. [[Barry loops: We should say more about this...]] [[comment 1: Mailto URIs focus on the message, not its submission. There is no way to specify envelope parameters, require encryption or authentication. Sure enough there is more than SMTP, so mailto is fine not to address this specific transport, but should we ever need more, it can not be specified as URI parameter, because there is no room in its namespace.]] [[comment 2: Michael tried to get documentation on SMTP-SMS gateways, but everybody operating one keeps the specification like a precious secret. From experiments made some years ago, we know some gateways ignore all messages with empty envelope senders, some do not implement MIME and some ignore the body. Using empty envelope senders to avoid loops is not possible and it would not allow to send notifications about bounces.]] Leiba & Haardt Expires June 10, 2006 [Page 5] Internet-Draft Sieve Notification Mechanism: mailto December 2005 3. Examples Triggering message (received by recipient@example.org): Return-Path: Received: from mail.example.com by mail.example.org for ; Wed, 7 Dec 2005 05:08:02 -0500 Received: from hobbies.example.com by mail.example.com for ; Wed, 7 Dec 2005 02:00:26 -0800 Message-ID: <1234567.89ABCDEF@example.com> Date: Wed, 07 Dec 2005 10:59:19 +0100 Precedence: list List-Id: Knitting Mailing List Sender: knitting-bounces@example.com Errors-To: knitting-bounces@example.com From: "Jeff Smith" To: "Knitting Mailing List" Subject: [Knitting] A new sweater I just finished a great new sweater! Sieve script (run on behalf of recipient@example.org): require ["notify", "variables"]; if header :contains "list-id" "knitting.example.com" { if header :matches "Subject" "[*] *" { notify :method "mailto:0123456789@sms.example.net" :message "From ${1} list: ${2}" :priority "3"; } } Notification message: Received: from mail.example.com by mail.example.org for ; Wed, 7 Dec 2005 05:08:02 -0500 Received: from hobbies.example.com by mail.example.com for ; Wed, 7 Dec 2005 02:00:26 -0800 Date: Wed, 7 Dec 2005 05:08:55 -0500 Message-ID: From: To: <0123456789@sms.example.net> Subject: From Knitting list: A new sweater Leiba & Haardt Expires June 10, 2006 [Page 6] Internet-Draft Sieve Notification Mechanism: mailto December 2005 Note that: o Fields such as "Message-ID" and "Date" were generated afresh for the notification message, and do not relate to the triggering message. o Additional "Received:" headers will be added to the notification message in transit; the ones shown were copied from the triggering message. o If this message should appear at the mail.example.org server again, the server can use the presence of a "mail.example.org" received line to avoid sending another notification. Leiba & Haardt Expires June 10, 2006 [Page 7] Internet-Draft Sieve Notification Mechanism: mailto December 2005 4. Internationalization Considerations [[Internationalization: What do we say here?]] Leiba & Haardt Expires June 10, 2006 [Page 8] Internet-Draft Sieve Notification Mechanism: mailto December 2005 5. Security Considerations Sending a notification is comparable with forwarding mail to the notification recipient. Care must be taken when forwarding mail automatically, to ensure that confidential information is not sent into an insecure environment. The automated sending of email messages exposes the system to mail loops, which can cause operational problems. Implementations of this specification MUST protect themselves against mail loops. Additional security considerations are discussed in [Sieve] and in [Notify]. Leiba & Haardt Expires June 10, 2006 [Page 9] Internet-Draft Sieve Notification Mechanism: mailto December 2005 6. IANA Considerations [[IANA to-do: What do we need to do to actually get this set up with IANA?]] The following template specifies the IANA registration of the Sieve notification mechanism specified in this document: To: iana@iana.org Subject: Registration of new Sieve notification mechanism Mechanism name: mailto Mechanism URI: draft-duerst-mailto-bis (change to RFC----) Mechanism-specific tags: none Standards Track/IESG-approved experimental RFC number: this RFC Person and email address to contact for further information: Michael Haardt This information should be added to the list of sieve notification mechanisms given on http://www.iana.org/assignments/sieve-notification. Leiba & Haardt Expires June 10, 2006 [Page 10] Internet-Draft Sieve Notification Mechanism: mailto December 2005 7. References 7.1 Normative References [Kwds] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [Notify] Melnikov, A., Ed., Leiba, B., Ed., Segmuller, W., and T. Martin, "Sieve Extension: Notifications", work in progress, draft-ietf-sieve-notify, December 2005. [Sieve] Guenther, P., Ed. and T. Showalter, Ed., "Sieve: An Email Filtering Language", work in progress, draft-ietf-sieve-3028bis, November 2005. [mailto] Duerst, M., Masinter, L., and J. Zawinski, "The mailto URI scheme", work in progress, draft-duerst-mailto-bis, February 2005. 7.2 Non-Normative References [ABNF] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 4234, October 2005. [Variables] Homme, K., "Sieve Extension: Variables", work in progress, draft-ietf-sieve-variables, October 2005. Authors' Addresses Barry Leiba IBM T.J. Watson Research Center 19 Skyline Drive Hawthorne, NY 10532 US Phone: +1 914 784 7941 Email: leiba@watson.ibm.com Leiba & Haardt Expires June 10, 2006 [Page 11] Internet-Draft Sieve Notification Mechanism: mailto December 2005 Michael Haardt freenet.de AG Willstaetter Str. 13 Duesseldorf, NRW 40549 Germany Phone: +49 241 53087 520 Email: michael.haardt@freenet-ag.de Leiba & Haardt Expires June 10, 2006 [Page 12] Internet-Draft Sieve Notification Mechanism: mailto December 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. 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