Thanks to muthshut for this excellent idea..Let me start of by how MS Exchange Differ from other Enterprise Messaging Solution.I have a company x owning x.com. If I have implemented my email with MS Exchange, not a single logs or database have to go out of my company wherein hosting with third party, we wont have that flexibility.
Now, If a company needs to get ISO certification n all those stuff... this comes into pictures....With other Messaging solution , I might have cost effectiveness, but what abt support ??When I say support, understand the fact that no product in this universe is 100 % reliable and thats a fact... when it comes to exchange, you dont have to panic..
If you are good at googling, you fix ya issues coz thats where exchange support comes into picture or if you ready to spend bucks right away, then call PSS... they will help you and get the issue resolved..Overall..., as a product and with the dedication MS has put into this product I dont have any complaints till date and it works like a charm