get meeting organizer mail address EWS API

I would like to get the meeting organizer mail address with the EWS API. Currently I'm just getting the a few properties of my appointment item. I heard that you can set which properties you want to get. My code looks like that:

CalendarView cview = new CalendarView(start, end);
                    cview.PropertySet = new PropertySet(BasePropertySet.FirstClassProperties);
                    FindItemsResults<Appointment> appResults = calenFolder.FindAppointments(cview);