Check out Davmail (http://davmail.sourceforge.net/ http://davmail.sourceforge.net/). I use this with offlineimap to run mutt with an Exchange installation; apar

Check out Davmail (http://davmail.sourceforge.net/ http://davmail.sourceforge.net/). I use this with offlineimap to run mutt with an Exchange installation; apart from calendar invitations, it works quite well.