Yesterday afternoon I synced my Galaxy S II with Microsoft Exchange and my multinational corporation's exchange server. Mail settings were to push at all times.
Over night my phone drained its battery completely and rang up 550MB in mobile upload charges via Exchange. I'm certain it was exchange because I have a traffic monitor tool and that particular email client is only holding my exchange account.
This was, to understate, surprising.
Is this normal behavior for Exchange? I only received 8 emails over night, none of which had any attachments to speak of.