My company is using Office 365, but as a software developer with a passion for *nix I really can’t live inside a windows environment. So for email use Thunderbird and the splendid Lightning addon together with a calendar provider for office 2010. It works great!
Thunderbird Lightning Calendar Office 2010
Using calendars from Office 365
Here you will find some of my thoughts and experiments from my daily life of programming and general geeking ;)