Network Working Group C. Newman Request for Comments: 3848 Sun Microsystems Category: Standards Track July 2004 ESMTP and LMTP Transmission Types Registration Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2004).
AbstractThis registers seven new mail transmission types (ESMTPA, ESMTPS, ESMTPSA, LMTP, LMTPA, LMTPS, LMTPSA) for use in the "with" clause of a Received header in an Internet message. 2], IANA maintains a registry  of "WITH protocol types" for use in the "with" clause of the Received header in an Internet message. This registry presently includes SMTP , and ESMTP . This specification updates the registry as follows: o The new keyword "ESMTPA" indicates the use of ESMTP when the SMTP AUTH  extension is also used and authentication is successfully achieved. o The new keyword "ESMTPS" indicates the use of ESMTP when STARTTLS  is also successfully negotiated to provide a strong transport encryption layer. o The new keyword "ESMTPSA" indicates the use of ESMTP when both STARTTLS and SMTP AUTH are successfully negotiated (the combination of ESMTPS and ESMTPA). o The new keyword "LMTP" indicates the use of LMTP .
o The new keyword "LMTPA" indicates the use of LMTP when the SMTP AUTH extension is also used and authentication is successfully achieved. o The new keyword "LMTPS" indicates the use of LMTP when STARTTLS is also successfully negotiated to provide a strong transport encryption layer. o The new keyword "LMTPSA" indicates the use of LMTP when both STARTTLS and SMTP AUTH are successfully negotiated (the combination of LSMTPS and LSMTPA). o The references for the ESMTP and SMTP entries in the registry should be updated to the latest specification  since both RFC 821 and RFC 1869  are obsoleted by RFC 2821.
and reduce their ability to correct security abuses after they happen. The result of such misguided efforts is usually a reduction of the overall security of the systems.  Hoffman, P., "SMTP Service Extension for Secure SMTP over Transport Layer Security", RFC 3207, February 2002.  Klensin, J., Ed., "Simple Mail Transfer Protocol", RFC 2821, April 2001.  Myers, J., "SMTP Service Extension for Authentication", RFC 2554, March 1999.  Myers, J., "Local Mail Transfer Protocol", RFC 2033, October 1996.  Klensin, J., Freed, N., Rose, M., Stefferud, E., and D. Crocker, "SMTP Service Extensions", STD 10, RFC 1869, November 1995.  Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC 821, August 1982. http://www.iana.org/assignments/mail-parameters>
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. 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. Intellectual Property 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- email@example.com. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society.