Exchange Server 2000 rocks [DotNetCentric].
Exchange? groan. Don't get me wrong, I like the idea of exchange and what it does, but the implementation sucks big time. At least in this servant's humble opinion. Perhaps I'll consider it serious enough when Kodiak finally ships and Exchange dumps that crappy old JET-based storage engine.
And please, don't even get me started on Exchange's little cousing; a piece of crap otherwise known as Sharepoint Portal Server.