I feel you pain,
I have tried everything from evolution 3.2.1 using:
to thunderbird 3.X/ and lightening using:
ii evolution-exchange 3.2.0-0ubuntu2 Exchange plugin for the Evolution groupware suite
and cannot get this piece of @#$!# to work. Davmail seems to be abit better of the options but if you dont know your paths to where the stuff is, it is useless. I will give you an update if I make progress. We just recently upgrade from exchange 2007 to 2010 to the pain has begun.