If you are deploying Exchange 2010 SP1 and have BES you should head over and read the Installation and Configuration Guide - http://docs.blackberry.com/en/admin/deliverables/14347/Configuring_Exchange_2010_environ_962756_11.jsp.
The guide covers most steps including configuring BES to run without public folders. There is one additional step to allow BAS to retrieve user information and is described in KB24470, Cannot add users to the BlackBerry Enterprise Server 5.0 in an environment that includes Microsoft Exchange 2010 SP1 - http://www.blackberry.com/btsc/search.do?cmd=displayKC&docType=kc&externalId=KB24470.
The workaround for now is to set the CONNECT_IGNORE_NO_PF flag in the MAPI profile used by the BlackBerry Mail Store Service in the following registry key.
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\BlackBerryServer\13dbb0c8aa05101a9bb000aa002fc45a
Locate the key 00036604 and change the second byte value to 80.
The examples provided are:
- If the value is currently set to 04 00 00 00, change it to 04 80 00 00 (see screen shot for example)
- If the value is currently set to 02 00 00 00, change it to 02 80 00 00
A restart of the BlackBerry Mail Store Service completes the workaround.