Sieve Working Group B. Leiba Internet-Draft IBM T.J. Watson Research Center Intended status: Standards Track M. Haardt Expires: September 8, 2007 freenet.de AG March 7, 2007 Sieve Notification Mechanism: mailto draft-ietf-sieve-notify-mailto-02 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 September 8, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Leiba & Haardt Expires September 8, 2007 [Page 1] Internet-Draft Sieve Notification Mechanism: mailto March 2007 Abstract This document describes a profile of the Sieve extension for notifications, to allow notifications to be sent by electronic mail. 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 ":importance" . . . . . . . . . . . . . . . . . . 4 2.3. Notify tag ":message" . . . . . . . . . . . . . . . . . . . 4 2.4. 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 . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . 13 Leiba & Haardt Expires September 8, 2007 [Page 2] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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]. 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 September 8, 2007 [Page 3] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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 headers with hname "from", "subject" and "received" are ignored if specified; all other URI headers are accepted. [[Barry ignored: Should we ignore them, or should their presence be an error?]] [[Michael ignored: The mailto URI spec allows for either. I like ignoring them more, because it fits into the picture of ignoring a different sender for other message-generating actions, if it is forbidden.]] [[Barry ignored 2: My thinking, when I suggested error, was that a script that explicitly tried to use them, even when this spec says "don't", would be broken. I see no reasonable scenario through which the mailto URI could be derived in a computed way that would include those fields, and thus justify ignoring them rather than considering them an error.]] 2.2. Notify tag ":importance" The :importance tag has no special meaning for this notification mechanism, and this specification puts no restriction on its use. Implementations MAY use the value of :importance to set a priority or importance indication on the notification message. 2.3. Notify tag ":message" o Unless overridden by ":from", the "From:" header field and the envelope sender of the notification message are set either to the envelope "to" field from the triggering message, as used by Sieve, or to a fixed address (so it "comes from the notification system"), at the discretion of the implementation. [[Barry sender: Alternative: the "from" is set to the envelope to, and the "sender" is set to the adderss of the notification system?]] Leiba & Haardt Expires September 8, 2007 [Page 4] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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 headers where the hname is "to"). o The "Received:" field from the triggering message are retained in the notification message, as these may help detect and prevent mail loops. o The "Subject:" field 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 by URI headers, or have implementation-specific values; their values are not defined here. It is suggested that the implementation capitalizes the first letter of URI headers and adds a space character after the colon between the mail header name and value when adding URI headers to the message. o If the mailto URI contains a "body" header, the value of that header is used as the body of the notification message. If there is no "body" header, the body of the notification message is empty. [[Barry body: I'd like some way to specify that the body contain some excerpt from the body of the triggering message. Does anyone else want this, or should we just say "Barry's being silly," and forget it?]] 2.4. Other Definitions Because the receipt of an email message is generating another email message, implementations MUST take steps to avoid mail loops. The notification message contains the "Received:" fields from the triggering message to allow loop detection as described in [RFC2821], section 6.2. The implementation MUST allow messages with empty envelope senders to trigger notifications. [[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 header, because there is no room in its namespace.]] Leiba & Haardt Expires September 8, 2007 [Page 5] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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}" :importance "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 September 8, 2007 [Page 6] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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:" fields 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 September 8, 2007 [Page 7] Internet-Draft Sieve Notification Mechanism: mailto March 2007 4. Internationalization Considerations [[Internationalization: What do we say here?]] Leiba & Haardt Expires September 8, 2007 [Page 8] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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 September 8, 2007 [Page 9] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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 September 8, 2007 [Page 10] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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 [RFC2821] Klensin, J., Ed., "Simple Mail Transfer Protocol", RFC 2821, April 2001. [Variables] Homme, K., "Sieve Extension: Variables", work in progress, draft-ietf-sieve-variables, October 2005. Leiba & Haardt Expires September 8, 2007 [Page 11] Internet-Draft Sieve Notification Mechanism: mailto March 2007 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 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 September 8, 2007 [Page 12] Internet-Draft Sieve Notification Mechanism: mailto March 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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. 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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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Leiba & Haardt Expires September 8, 2007 [Page 13]