Re: The insane thing about it is...
You’ve never worked with Exchange Server have you?
First off, many companies consider Email mission critical. Email is customer facing, and it’s used by everyone. I’d rather have the accounting system down for a few hours than email.
Second, Exchange Server is complicated... When you have hundreds/thousands of users it becomes a b1tch to maintain. Try managing spam, phishing, archival (legal), backups, etc. is a pain in the a$$.