Hi, I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. The document is well thought out, but I have some minor comments: 1. The security considerations sections has lots of information and pointers. It looks pretty complete. It even has the every-smtp-rfc-mandatory-reference to spam. :) 2. The document uses a bunch of traditional x.400 messaging terms (e.g., MHS, MTA, MUA) to describe the SMTP mail system. I know it's picky, but if we're going to write a document that uses x.400 terms we may want to cite that work in an informal reference. Pat