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.
It’s SMTP. You actually DON’T control the data.
You know, mail sent from others. Without the Internet (and Cloud is just a fancy term for storing something on the Internet), SMTP is pretty worthless.
As I tell people, you lost “control” when you first plugged into it. Not the cloud, but rather the Internet.