I very much dislike Microsoft Outlook. I think it is a great example of Microsoft's surprisingly poor ability to design usable software. It ruins my days in myriad ways, but today I am struggling to figure out how to put a person into an Address Book entry -- or is it a Contact? no wait, I think it's a Group Member. Wait, is that right? Uh, why did I add this person to the Address Book (or was it a Contact?) and then they don't show up in my Group (or is that an Address Book entry?).
The thing that bothers me is that there are many email programs which are perfectly sensible, and it baffles me why Microsoft doesn't just copy one of them. It's not as though email is a brand new concept without well-formed paradigms. If Microsoft wants to radically rethink how email is used, why wouldn't they improve it instead of wrecking it?