Fax Working Group Dan Wing Internet Draft Cisco Systems July 30, 1998 Expires December 1998 draft-ietf-fax-mdn-multipart-00.txt Extensions to Message Disposition Notifications for Reporting on Multipart/Alternative Messages Status of this memo This document is an Internet-Draft. 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." To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Copyright Notice Copyright (C) The Internet Society (1998). All Rights Reserved. 1. Abstract This document describes new Message Disposition Notifications fields [MDN] which allows a sender to request a recipient to identify which part(s) of a multipart/alternative message were processed by the recipient's mail user agent (MUA). 2. Introduction With the proliferation of attachments, it is often useful for a sender to know which attachements were renderable by a recipient. For multipart/alternative, subsequent messages can suppress unnecessary alternatives if the recipient has successfully processed a certain alternative in a previous message exchange. 2.1. Discussion of this Draft This draft is being discussed on the "ietf-fax" mailing list. To subscribe, send a message to: ietf-fax-request@imc.org with the line: subscribe in the body of the message. Archives are available from http://www.imc.org/ietf-fax. 3. Extension to Message Disposition Notifications If a sender is interested in knowing which parts of a multipart/alternative message were usable by the recipient's MUA, the sender MUST include the "Disposition-Notification-To" and "Content-ID" heders headers on each MIME part it is interested in. When the recipient's MUA sees the Disposition-Notification-To on an individual MIME part, the recipient's MUA will generate an MDN for that part if that part is processed by any of the disposition-type described in section 3.2.6 of [MDN]. The generated MDN will contain the new "Original-Content-ID" field described in section 3.2. 3.1. Deciding when to generate an MDN The recipient's MUA MUST NOT generate an MDN for parts which were not used by the MUA. For example, in a multipart/alternative only one of the parts is displayed or processed; the other parts are not used. If the recipient's MUA attempted to decode a media type it expected to decode, such as an image/gif when the MUA includes an GIF viewer, but the GIF was corrupted, the MUA should generate an MDN indicating that an error occured while processing that part [MDN-ERROR]. If the corrupted part is enclosed in multipart/alternative, the MUA may attempt to process one of the alternatives, which may cause generation of another MDN. XXX - how to prevent generation of multiple MDNs (which is illegal)? 3.2. Original-Content-ID field The Original-Content-ID indicates which part of a multipart is being reported on. The syntax for this field, per the format described in [ABNF], is: extension-field = "Original-Content-ID" ":" content-id The token is the Content-ID that was specified in the multipart that caused generation of this MDN. 4. Security Considerations In addition to the security considerations described in [MDN], this extention provides additional information to the sender. For example, knowledge of the successful or unsuccessful processing of a cryptographically signed message can tell a sender if the recipient is authenticating messages or simply ignoring the cryptographic signature. 5. Examples 5.1. MDN issued after a mesage was successfully processed This is a multipart/alternative message which contains text/plain, text/enriched [ENRICHED], and text/html [MHTML] media types. The sender requested an MDN in the RFC822 headers, and also requested an MDN on each part of the multipart message and provided a Content-ID for each of those parts. Return-Path: Received: from gw.cisco.com by HQ.Cisco.COM with ESMTP; Fri, 5 Dec 1997 14:02:00 -0800 Received: from yoyodyne.com by gw.cisco.com with SMTP; Fri, 5 Dec 1997 14:01:45 -0800 From: Jane Sender To: Joe Recipient Original-Recipient: rfc822;Joe_Recipient@cisco.com Date: Fri, 5 Dec 1997 14:01:23 -0800 Message-ID: <19971205.140123@yoyodyne.com> MIME-Version: 1.0 Disposition-Notification-To: Jane_Sender@yoyodyne.com Content-Type: multipart/alternative; boundary="ABCDEF" --ABCDEF Content-Type: text/plain Content-ID: <19971205.140000.812@yoyodyne.com> Disposition-Notification-To: Jane_Sender@yoyodyne.com This is a test --ABCDEF Content-Type: text/enriched Content-ID: <19971205.140000.813@yoyodyne.com> Disposition-Notification-To: Jane_Sender@yoyodyne.com This is a test. --ABCDEF Content-Type: text/html Content-ID: <19971205.140000.814@yoyodyne.com> Disposition-Notification-To: Jane_Sender@yoyodyne.com red and green colors This is a test. --ABCDEF-- The recipient's MUA selected the text/enriched part for display and sent the following MDN. Date: Fri, 5 Dec 1997 14:03:06 -0800 From: Joe Recipient > Message-Id: <19971205.14030618@hq.cisco.com> Subject: Disposition notification To: Jane Sender MIME-Version: 1.0 Content-Type: multipart/report; boundary="NextPart"; report-type=disposition-notification; --NextPart Your message sent on Friday, 5 Dec 1997 at 14:00 to Joe Recipient with the subject "Hello there" has been displayed. This is no guarantee that the message has been read or understood. --NextPart Content-Type: message/disposition-notification Reporting-UA: hq.cisco.com; MultiNet Original-Recipient: rfc822;Joe_Recipient@cisco.com Final-Recipient: rfc822;Joe_Recipient@hq.cisco.com Original-Message-ID: <19971205.140123@yoyodyne.com> Disposition: manual-action/MDN-sent-manually; displayed Original-Content-ID: <19971205.140000.813@yoyodyne.com> --NextPart-- 6. Acknowledgments XXX 7. References [ABNF] D. Crocker, P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [ENRICHED] P. Resnick, A. Walker, "The text/enriched MIME Content-type", RFC 1523, February 1996. [MDN] R. Fajman, "An Extensible Message Format for Message Disposition Notifications", Internet Draft, Work in Progress, draft-ietf-receipt-mdn-XX.txt (soon to be Proposed Standard) [MDN-ERROR] D. Wing, "Format of Message Delivery Notifications to Indicate Processing Errors", Internet Draft, Work in Progress, draft-ietf-XXX-mdn-error-XX.txt. [MHTML] J. Palme, A. Hopmann, "MIME E-mail Encapsulation of Aggregate Documents, such as HTML (MHTML)", RFC 2110, March 1997. 9. Copyright Copyright (C) The Internet Society 1997. All Rights Reserved. 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This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. 10. Authors' Addresses Dan Wing Cisco Systems, Inc. 101 Cooper Street Santa Cruz, CA 95060 USA Phone: +1 408 457 5200 Fax: +1 408 457 5208 EMail: dwing@cisco.com