How many hours per week, on average, does it take to administer Microsoft Exchange 2013? I run a mid-size company & my IT staff is considering moving to Exchange from another email platform. Any real-world metrics would be helpful. Thanks!

This is really a tricky question with no defined answer, it all depends on the things how configured in your Exchange environment, how are process defined around (or how you want to make process around in another word), how do you make automation with PowerShell, how do your users understand the product and raising questions/support tickets. Last but not least, what information you want to give to end-users on their requests etc...