We tell our users to accept and decline meeting appts only from their outlook clients. We have always run into issues with doing it from the blackberries. As far as the from BESAdmin an behalf of the user, the BESAdmin account has “send as” permissions on the exchange account. Do they see this on replies to emaiuls from the blackberry as well? I don’t recall hearing this complaint from any of our users. You might talk to BB support to find out if something is configured in a way that is causing this that can be changed.