Dear all, 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. **** Technical: **** The two numbered bullets in page 5 (section 2.2) and the first and third bullets in page 6 (Section 2.2) should use RFC2119 language. **** Nits: **** Section 1: > his extension allows a client to search multiple mailboxes > with one command, limiting round trips delay Maybe something like "transaction delay" or something along those lines would be better? Section 1: > There is > now implementation experience, giving confidence in the protocol, so > this document puts the extension on the Standards Track, with some > minor updates that were informed by the implementation experience. You may want to replace "informed" with "motivated". Thank you, Tina