I figured it's been some time and many releases of SM so I'll give Mac Mail a try again using Exchange as I have both EWS and EAS and realize Mac Mail uses EWS. I've been using IMAP since Mac Mail and Exchange were trouble before I made the switch to IMAP to make it work. Sadly, after about two days I've again deleted the Exchange accounts and have gone back to IMAP. While the setup was fine and the initial load of email is fine, it never syncs. I have it in use on 3 Mac's and syncing was just dead in the water. I had to reset the mailbox in Mac Mail, close and restart and it would sync again. I doubt the blame is the Mac side as obviously they have a larger userbase. I give up on EWS in Mac Mail.