Many Linux users out there deal with the daily frustration of trying to work with Exchange servers - most recently the biggest headaches come from connection issues to Exchange2007.
Evolution's Exchange Connector only partly bridges this gap. It interfaces via http(s) with Exchange 2000 or 2003 Outlook Web Access (OWA) and allows basic email functionality. As of the 2.25 build of Evolution, it is still NOT compatible with Exchange 2007.
Enter: Evolution Mapi-Provider. Developed under OpenChange, this plugin extends Evolution, and provides direct interoperability with Microsoft Exchange servers using native (MAPI) protocols. This delivers a more complete feature set approaching that of Microsoft Outlook and allows client connection to all versions of Exchange servers.
I have been using this plugin and have been very pleased with the performance. It is still a work in progress and has suffered a licensing setback recently which resulted in ALL binaries being removed from SuSE and Fedora repos. Correction of the license issue is in the works and the binaries will return soon. Full integration of this plugin with Evolution is expected in the upcoming Gnome 2.26 release.
More info can be found below:
OpenChange - Evolution Plugin
MAPIProvider - Evolution