You should try it some time, just for the learning exercise :)

I won’t invalidate the writers experience , I just want to add that that hasn’t been my experience with properly configured environments (not saying the writers was improperly configured, it clearly wasn’t).

Has this been your experience?

I like email the way it is and believe it functions as most people desire.

Everything you mention already exists for email (ie discussion groups exist, encryption exists, etc…)

The key thing is that it works now and you can easily host your own mail server to achieve whatever you desire feature wise