In ActiveSync, if I clear the check box for a folder that has been synchronized to the mobile device, does that action delete the items from the Exchange server?
No. When you disable synchronization for any folder on your mobile device, only the data that is stored on the device is deleted. Data that is stored on the Exchange server remains intact. If you disable the synchronization of a folder on your mobile device, ActiveSync on the device prompts you with the following message: All e-mail synchronized to your device using ActiveSync must be removed to proceed. Select OK to continue. You can then confirm that you want to disable synchronization of the folder.