A New Internet-Draft is available from the on-line Internet-Drafts directories.
Abstract: «Lightweight MTA Authentication Protocol (LMAP) is the general term for a a family of proposed protocols to help address the spam problem by better authenticating mail senders. This document discusses the applicability, and the costs and benefits of wide-spread deployment of the protocol, and compares the various LMAP proposals.»
http://www.ietf.org/internet-drafts/draft-irtf-asrg-lmap-discussion-00.txt