Uhm...places like Comcast GAVE UP trying to get Microsoft to handle JUST THEIR OWN ACCOUNTS. They're using Zimbra, which works so much better.
An airport in Indy has two men who do NOTHING but rebuilt Microsoft servers each week, rolling them back into service the next week, because Microsoft is a TINY NUMBER OF PROGRAMMERS. It can't do the job Linux is doing.
But then, that's why people are leaving Microsoft in droves. (It sounds like Windows 8 isn't the end of their new failures!)