Network Working Group Jacob Palme Internet Draft Stockholm University/KTH draft-ietf-drums-mail-followup-to-00b.txt Expires: May 1998 November 1997 The "Mail-Followup-To" header field Status of this Document 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), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). NOTE: This document is a proposal for text to be incorporated in the new message format standard or published as a separate RFC. It is written as input for discussions in the drums working group and does not yet reflect any consensus within that group. Abstract This proposal contains a proposed new e-mail header field "Mail-Followup-To", which is intended to be used instead of the "Reply-To" header field for suggesting where replies to the group who participates in a discussion should be sent. Temporary note This proposal does not represent any consensus opinion in the drums working group at this time (21 November 1997). Table of Contents 1. Introduction 2. The "Mail-Followup-To" Header field 2.1 Syntax 2.2 Sender action 2.3 Mailing list action 2.4 Mail Client Action 2.5 Usenet News Client Action 2.6 A note about the "From:" header field 2.7 Security Considerations 3. The "Message-ID" Header field 3.1 Relation of changes "Message-ID" and other header fields and body 3.2 Security Considerations 4. Copyright 5. Acknowledgments 6. References 7. Contact Information 7.1 Author's Addresses 7.2 Working Group Chairman 7.3 Applications Area Director(s): 7.4 Area Advisor 7.5 Mailing lists: 1. Introduction The "Reply-To" e-mail header field is known to be problematic because it is used for different purposes by different mailers and when the mailer inserting this header field and the mailer using the header field interpret it in different ways, unexpected results can happen. For example, a message intended for the author of a previous message only may by mistake be sent to a mailing list. One way to reduce this problem is to define a new header field "Mail-Followup-To" which replaces "Reply-To" in recommending recipients for replies destined for the group of people discussing an issue. 2. The "Mail-Followup-To" Header field 2.1 Definitions Group Reply Reply intended for the group of people who are discussing an issue. This is often all or most of the people who got the replied-to message. However, some receipients may not want to participate in the full discussion. Also, in some cases a discussion may be initiated by a cross-posted message to several lists, but further discussion continued in only one of them. Finally, recipients of the replied-to message may be omitted to avoid sending them duplicates of the message. "From"/"Reply-To" The value of the "Reply-To" header field, or if there is no such header field, the value of the From header field. 2.2 Syntax "Mail-Followup-To" = "Mail-Followup-To" mailbox-list CRLF 2.3 Sender action The "Mail-Followup-To" header field can be inserted by the sender of a message to indicate suggestions on where group replies to it are to be sent. Here are some ways of constructing this header field: 1. Recipients of the previous message taken from the "From"/"Reply-To", "To" and "CC" header fields. Note that omitting any "Mail-Followup-To:" header field is not the same thing, it does not give the protection described in point 4. below. If however, the sender knows that the mailing list expander will not add a "Mail-Followup-To:" header field, and the sender wants replies to all recipients, the sender can omit the "Mail-Followup-To" header field. 2. When a message is sent to a mailing list, and the author is a member of this list, and wants to get only one copy of replies, the author can be omitted from the "Mail-Followup-To" header field. 3. When a message is sent to several mailing lists, but the author suggests that further discussion should take place only in one of them, the names of the other lists can be omitted from the header field. This is similar to the usage of the "Followup-To" header field in Usenet News. 4 When a message is sent to several mailing lists, and the sender wants to stop one of the lists adding the Mail- Followup-To header field (reducing replies to only one of the lists), this header field can be set by the author to refer to all the cross-posted lists. 5. When a message is sent to a mailing list, which contains sublists, there is a risk that the sublists will insert "Reply-To" or "Mail-Follow-Up-To" header fields referring to the sublist. If this happens, replies might be sent to the sublist, and thus not reaching the full set of readers of the primary mailing list. Use of the "Mail-Followup-To" can be used by the author or the primary mailing list to stop sublists inserting "Mail-Followup-To" in the header field. 2.4 Mailing list action A mailing list expander may insert the "Mail-Followup-To" header field, with a reference to the list, if there is no previous "Mail-Followup-To" in the message. A mailing list expander SHOULD NOT change an existing "Mail-Followup-To" header field, since this may reduce the set of recipients suggested in the original message. If a message has a "Followup-To" header field, indicating a suggestion for further discussion in a newsgroup, a mailing list expander SHOULD NOT insert "Mail-Followup-To" except to refer to a mailing list which is gatewayed to the newsgroup in the "Followup-To" header field. A message should not contain both a "Followup-To" referring to a newsgroup and a "Mail-Followup-To" referring to a mailing list which is gatewayed to and from that newsgroup, so if such a "Mail-Followup-To" is inserted, the "Followup-To" SHOULD be removed. 2.5 Mail Client Action The "Mail-Followup-To" contains a suggestion to the recipient of where to send group replies, but the recipient SHOULD be free to choose other recipients of a reply. If a mail client contains a command intended to write a reply to the group of recipients of a message, the value of the "Mail-Followup-To" SHOULD be used instead of the merge of the "From"/"Reply-To", "To:" and "Cc:" fields in construction a default suggested set of recipients for such a reply. 2.6 Usenet News Client Action If a message has a "Mail-Followup-To" header field, and no "Followup-To" header field, this is an indication that further discussion should take place only in e-mail, not in Usenet News, and thus a Usenet News client SHOULD NOT automatically assemble a proposed set of recipients which includes any Usenet News newsgroup. Instead, the "Mail-Followup-To" header field should be used also by the Usenet News client in suggesting a default set of reply recipients to its users. 2.7 Security Considerations There are no particular security risks with the "Mail-Followup-To" if implemented correctly. Instead, they will reduce the security risk of having personal messages inadvertently sent to more recipients than intended. 3. Copyright Copyright (C) The Internet Society (date). 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 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. 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. 4. Acknowledgments Chris Newman and several other people have helped me with preparing this document. I alone take responsibility for any errors which may still be in the document. 5. References Not ready 6. Contact Information 6.1 Author's Addresses Jacob Palme Phone: +46-8-16 16 67 Stockholm University and KTH Fax: +46-8-783 08 29 Electrum 230 Email: jpalme@dsv.su.se S-164 40 Kista, Sweden 6.2 Working Group Chairman Chris Newman 6.3 Applications Area Director(s): Keith Moore Harald Alvestrand 6.4 Area Advisor Harald Alvestrand 6.5 Mailing lists: General Discussion:drums@cs.utk.edu To Subscribe: drums-request@cs.utk.edu Archive: ftp://cs.utk.edu/pub/drums/mail-archive/