I have searched the archives and haven't found this discussed. I have an Exchange server and have been using Entourage but it is choking on the large number of emails and thus the database checker spends the first half of every day rebuilding itself. I decided to try "Mail" as my client as it supports Exchange server as well. I like Mail better than Entourage but it is slower to update than Entourage on my many Exchange folders. My biggest issue now though is that it is not updating Exchange with the changes to my messages. Meaning, if I delete or move a message in Mail, it does not reflect that change on Exchange (I also view my mail on 2 PC's with Outlook). I do select "auto sync mailbox" (images below) and it will update the server when I first select it but then stops and if I swith from password to NTLM it will update again but stop so I switch back again, etc, etc. Is there any way to make this work all of the time without having to force it by switching methods?