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. 0. note: the document expired today 1. editorial COMMENTS: - I ran idnit and received three errors and two warnings. Considering the long life time of this draft this might be natural, but still at least the errors must be resolved. - the document should have a proper TOC and proper page headers and footers. - the document uses a "work in progress" document as a normative(!) reference [UNICASEMAP]. It should be changed to informative or the draft should not proceed to proposed standard until the reference is stable. - additionally a HTML link is cited inside the I-D for the informative reference [THREADING], maybe this reference can be published somewhere more stable too? - in the document are several cases with double blanks between sentences. This is not good and should be removed by the authors or the editor before publication. 2. COMMENT section 3 - REFERENCE refers to a product version ("Netscape Mail and News" versions 2.0 through 3.0) which I would consider bad style or even inappropriate for a proposed standard. Consider the time in the future that this standard might be valid and that people may not recall a specific product name or version. 3. COMMENT on section 3 - ORDEREDSUBJECT A Note refers to former outdated I-D version. I would recommend to remove any reference to outdated and no longer valid I-Ds. 4. COMMENT (some of this may at the discretion of the AD also be a DISCUSS) is section 6 Security Considerations: 4.1. you should not only state the deficiencies of IMAP, but also at least require with a "SHOULD" the authentication of commands and protection of data on the wire via encryption (e.g. TLS). 4.2. you should mention that using sorting by reference/thread can lead to wrong references (trees) if more than one email exists with the same ID (UID/message-sequence/...) and child-messages are grouped to a father-message. An attacker might use the fact that these values are not well protected and the sorting algorithm reaction to such ambiguity to hide messages respectively sorting (relocating) them to a different thread. 4.3. the pre-sorting stripping of the subject of all re and fw headers to identify the base subject (described in section 2.1) may lead to actually loosing the right context (end in the worng sorting thread and/or level) if emails are created where the specified magic letters are legitimate text at the beginning of the subject. For example in a foreign language the text "RE" might not be used for reply but actually have a different real meaning. Best regards, Tobias _______________________________________________ IETF mailing list IETF@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf