Originally Posted by bigyin
Just verified the permissions on the BES admin account. you will need to have your IT admin check this setting for the "send as " and " recieve as " permissions are set on the BES admin account, It WILL CURE THIS ISSUE !
I believe it also needs "Administer Information Store" as well.
If all that checks out, I would take a peak at the debug logs (the MAGT ones) to see if there are any CDO exceptions occurring when you try to create/update/delete an appointment from the handheld.