Internet-Draft Ncc in Mail Header Arun Sankar Hewlett-Packard Company Expires: September 11, 2004 March 11, 2004 Ncc in Mail Header 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 The list of Internet-Draft Shadow Directories can be accessed at . Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This draft presents a mechanism to simplify one of the cumbersome aspects of mailing. The basic intention is to minimize the complication when a mail needs to be sent to n - m mail IDs i.e. send it to a group Id of n and exclude m from the alias [ALIAS] list. 1. Introduction The current situation is that when a mail is to be sent to an alias [ALIAS] list, there is no possible way of a negating a set of mail IDs from that list. The purpose of this draft is a solution by the addition of another field in the Mail header. The intention is to achieve this negation of a mail IDs from an alias [ALIAS]. 2. Conventions Used in this Document The key words "REQUIRED", "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as described in "Key words for use in RFCs to Indicate Requirement Levels" [KEYWORDS]. Arun Sankar Expires September 11, 2004 [Page 1] Internet-Draft Ncc in Mail Header March 11 2003 3. Requirement The requirement is to provide the user with a field, using which mails can be sent to a subset of an alias [ALIAS], i.e. a provision "not" to deliver the mail to a set of mail IDs from the alias [ALIAS]. 4. Header Updations A new field needs to be added into the SMTP header [RECEIVER FIELDS] called "Ncc". This would act as a negation to the To, Cc and Bcc fields and ensure the mail is not sent to the mail ID mentioned in the "Ncc" field. The Ncc field SHOULD be a part of the mail envelope directly or indirectly in the implementation. 5. Format of the Field The format specification of this field should be treated as a "Cc" field. This field would be a part of the header and would be carried forward throughout the mail thread. 6. The SMTP service extension for Ncc The Ncc option MAY not be implemented in all Mail Servers. This SHOULD not affect the servers that have implemented Ncc. The client can figure out if the server has Ncc implemented using the EHLO command transaction. When the client sends the EHLO command, the server responds with "NCC". E.g. S: 220 test1.example.com ESMTP server ready C: EHLO test2.example.com S: 250-test1.example.com S: 250 NCC If the server does not respond with an Ncc, the mail SHOULD not be processed further but a suitable error message like "NCC" not supported should be sent back to the sender. 6. Processing of the Ncc Field. The Ncc Field MUST be processed after the alias [ALIAS] has been expanded. The mail IDs in the Ncc field MUST be removed from the To, Cc and the Bcc fields during its processing. This field MUST be treated similar to the Cc field and processing has to be done in mail gateways, relays etc. The Ncc field has to be a part of the mail envelope. Its existence in the envelope is necessary as the alias expansion can happen in any intermediate server. This field can directly be a part of the envelope or it can exist through a envelope flag that can mention that the Ncc field is Non-Null. Arun Sankar Expires September 11, 2004 [Page 2] Internet-Draft Ncc in Mail Header March 11 2003 7. Example A needs to send a mail to a group but the intention is not to send this to D. From: A From: A To: B To: B CC: C,E,F,G,H CC: Team_ABCDEFGH nCC: D Subject: TEST Subject: TEST On the continuation of the thread and D is still not a part of the list. From: B From: B To: A To: A CC: C,E,F,G,H CC: Team_ABCDEFGH nCC: D Subject: TEST Subject: TEST Appendices A. References The following documents contain definitions or specifications that are necessary to understand this document properly: [ALIAS] J. Klensin, "Simple Mail Transfer Protocol", RFC: 2821, April 2001 [RECEIVER FIELDS] Crocker, D., "Standard of the Format of ARPA Internet Text Messages", RFC 822, August 1982. [KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Author's Address Arun Sankar Hewlett-Packard, 29, Cunningham road, Bangalore, India 560052 sankar@hp.com +91-80-205-3107 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it Arun Sankar Expires August 6, 2004 [Page 3] Internet-Draft Ncc in Mail Header March 11 2003 has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. 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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. Arun Sankar Expires September 11, 2004 [Page 4]