Google Apps all the way. No need to do the big corporate thing of hosting your own service. Concentrate on what you know best.
not sure if anyone mentioned in replies: try outlook.com it’super simple and takes minutes (10’s of them) to setup awesome interface
but microsoft has gone out of its way for to make it look super confusing send me a pm if u need help setting up. i’m a super expert in setting up (i’ve done 1 domain and am planning to do another!!!)
I used gmail for my personal and office use,it is easy oprate compare to other search engines.