ExQuilla

ExQuilla is an addon for Mozilla's http://alternativeto.net/software/mozilla-thunderbird/ email client that allows access to both messages and contacts stored on http://alternativeto.net/software/microsoft-exchange-server/ 2007 or 2010. ExQuilla uses EWS (Exchange Web Services) for access to the server. ExQuilla (beginning with release 24) will work with either Thunderbird 17.* or 24.* on Windows, Linux, and OSX platforms.