I have a few issues with my BES server. first of all the email reconciliation is not working properly - it takes over 20 minutes even longer or never to update read message from Outlook to the handheld. Any suggestions? I also am using MSDE and have about 45 users - is it time to change it to a SQL DB? how many high traffic users can MSDE support?

depends more on how much you have going on on the bes server and whether you mapped permissions right during setup.

As a rule of thumb sql server is always better than running msde and with 45 people you might just have issues.

20 minutes sounds about right, If you do a "reconcile now" does it go through immediately?