We have an employee using Office XP whose email is configured externally (i.e. he uses our domain providers mail server and not our internal one (we use Microsoft Mail) like everyone else). When attempting to set an appointment and send it in a manner so the recipient can accept or reject it the receiver only receives a text file and not the usual GUI with the accept/reject/reschedule buttons on it. Does anyone have an idea what can be causing this? Is it because of our Microsoft Mail server or something else?