Spits (coffee...)
Dude, seriously? Their on-premises burden of a messaging server???
That's the first thing I gave up when Cloud Services started. Went Exchange Online and never looked back.
Without Internet connectivity, messaging servers are, well, useless?
So why run it locally? Get it all from the Web.
I say this as a MCSE, Messaging, since Windows NT. I have certified on Exchange 5.0 all the way to 2013. We had 25K+ accounts. I gave it all up for Exchange Online. AND, I no longer get calls at O'Dark 30 to come in and fix email.
And before I go, I love Windows Server 2016. I even use it as my desktop.
I was speaking generally. Personally, I think exchange is a cluster. I hate having to deal with it. However, Microsoft has convince a lot of its die-hard drones that it is the only messaging platform for large corps.
Where I work, I was just converted to O365, which is an even worse mistake IMO.
So why run it locally? Get it all from the Web.
Because if you don't control your data, you don't control your data.
If your data is in the 'cloud', you have given up control of your data. For many companies, this data is a very real asset. I do not think it's necessarily a good idea to give that away, especially if there are privacy implications.