Re: Exchange is bad news...
I feel it my duty to shill Zimbra at this point. I was moving from Small Bastard Server and needed a replacement for Exchange so I look at other options.
No, it's not mainstream but it's a hellofalot cheaper than on-prem Exchange and does the same job. Your users even have the choice of native webmail or Outlook.
If you need support, it's actually very good.
Try it free at home if you don't believe me!
Sadly my PHB has decided that we need to embrace O365 so we'll be making the final migration "soon" - or as soon as I don't have anything else more pressing to do.