See my reply below. My draft originally included the mail relaying case but trying to address both submission and relaying in the same document made the docume

See my reply below. My draft originally included the mail relaying case but trying to address both submission and relaying in the same document made the document unwieldy. In theory they both use the same protocol (more-or-less) but there are numerous subtle differences that make the two cases vastly different when negotiating encryption. The IETF UTA working group has documents in process to address the mail relaying case; I'm sure they'd appreciate review and feedback.