Internet Draft: Notify Mail R. Gellens Document: draft-gellens-notify-mail-01.txt QUALCOMM Expires: June 2005 December 2004 Simple New Mail Notification 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 RFC 3668. By submitting this Internet-Draft, I accept the provisions of Section 3 of RFC 3667 (BCP 78). 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. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This memo documents a long-standing technique, supported by a large number of mail servers, which allows users to be notified of new mail. In addition to server support, there are a number of clients which support this, ranging from full email clients to specialized clients whose only purpose is to receive new mail notifications and Gellens Expires June 2005 [Page 1] Internet Draft Notify Mail December 2004 alert a mail client. In brief, the technique is for the server to send the string "nm_notifyuser" to the finger port on the IP address (either configured or last used) for the user who has received new mail. Gellens Expires June 2005 [Page 2] Internet Draft Notify Mail December 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions Used in this Document . . . . . . . . . . . . . . 3 3. Simple Mail Notification . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4 7. Normative References . . . . . . . . . . . . . . . . . . . . 4 8. Informative References . . . . . . . . . . . . . . . . . . . . 4 9. Author's Addresses . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property Statement . . . . . . . . . . . . . . . . 5 Full Copyright Statement . . . . . . . . . . . . . . . . . . . 5 Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction There is a long-standing technique supported by a large number of mail servers which allows users to be notified of new mail. In addition to server support, there are a number of clients which support this, ranging from full email clients to specialized clients whose only purpose is to receive new mail notifications and alert a mail client. This technique is sometimes known as "notify mail" (after a shareware client of the same name), sometimes called "biff", and sometimes the "finger hack". 2. Conventions Used in this Document In examples, "C:" is used to indicate lines sent by the client, and "S:" indicates those sent by the server. Line breaks within a command example are for editorial purposes only. Examples use the 'example.net' domain. The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as defined in [KEYWORDS]. 3. Simple Mail Notification The technique is for the server to send the string "nm_notifyuser" to the finger port on the IP address for the user who has received new mail. Gellens Expires June 2005 [Page 3] Internet Draft Notify Mail December 2004 The IP address to use may be configured, or the server may use the IP address that was last used to check mail by the user. Typically this is a per-account configuration option. To be useful, on the client system a process must be listening to the finger port. When it received the "nm_notifyuser" string, it takes a configured action, typically instructing a mail client to fetch mail. Normally, a TCP connection to the target computer is opened, the "nm_notifyuser" string is sent, and the connection is closed without waiting for any response. In some cases UDP is used instead of TCP. 4. Security Considerations There is of course no assurance that in general the "nm_notifyuser" message is being sent to the correct IP address. Nor does the listening agent on the client system have any assurance that a "nm_notifyuser" string was sent by a mail server which has received new mail for the user. It would be trivial for an attacker to send large numbers of "nm_notifyuser" messages to any targeted system. Client systems listening for this message SHOULD implement protections against being flooded with notifications. Many server systems already implement protections against users logging in and checking mail too frequently. 5. IANA Considerations None at this time. 6. Acknowledgments The NotifyMail shareware utility was written by Scott Gruby. 7. Normative References [KEYWORDS] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", March 1997, BCP 14, RFC 2119, Gellens Expires June 2005 [Page 4] Internet Draft Notify Mail December 2004 8. Informative References None. 9. Author's Addresses Randall Gellens QUALCOMM Incorporated 6455 Lusk Blvd. San Diego, CA 92121-2779 USA randy@qualcomm.Com Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights 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; nor does it represent that it has made any independent effort to identify any such rights. 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. Full Copyright Statement Copyright (C) The Internet Society (2004). 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. Gellens Expires June 2005 [Page 5] Internet Draft Notify Mail December 2004 Disclaimer This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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. Gellens Expires June 2005 [Page 6]