Internet Engineering Task Force P. Hallam-Baker Internet-Draft VeriSign Inc Intended status: Informational July 2, 2008 Expires: January 3, 2009 DKIM Extensions draft-hallambaker-dkim-extensions-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 January 3, 2009. Abstract A DKIM Policy statement is defined for the policy 'this zone never sends mail'. Hallam-Baker Expires January 3, 2009 [Page 1] Internet-Draft DKIM Extensions July 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3 2. NoMail Policy . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 3 Intellectual Property and Copyright Statements . . . . . . . . . . 5 Hallam-Baker Expires January 3, 2009 [Page 2] Internet-Draft DKIM Extensions July 2008 1. Introduction 1.1. Requirements Language 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 RFC 2119 [RFC2119]. 2. NoMail Policy The NOMAIL policy is declared in an SSP record using the tag "NOMAIL". No parameters are specified for the NOMAIL policy. If specified the NOMAIL policy states that no mail is sent from the domain to which it is attached. All mail that purports to have been sent by that domain MUST be considered suspicious. 3. Acknowledgements The ideas in this document arose from extensive discussions with the DKIM working group, in particular Hector Santos and others. 4. IANA Considerations This document requests allocation of a DKIM SSP tag 'NOMAIL' 5. Security Considerations The NOMAIL policy MAY be employed to perform a denial of service attack. 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Hallam-Baker Expires January 3, 2009 [Page 3] Internet-Draft DKIM Extensions July 2008 Author's Address Phillip Hallam-Baker VeriSign Inc Email: pbaker@verisign.com Hallam-Baker Expires January 3, 2009 [Page 4] Internet-Draft DKIM Extensions July 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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. Hallam-Baker Expires January 3, 2009 [Page 5]