I meant it tongue-in-cheek when I said "facebook generation", but it seems we really have a generational gap here.

The code needs to be open source, versioned, vetted, and only obtained via a trusted repository

http://www.procmail.org http://www.mozilla.org/en-US/thunderbird/ http://www.mutt.org/

The user is no longer instantly able to access the latest version of the application by simply typing in a URI.

Yes, that actually bothers me a lot. Can you imagine the crazy effort that I go through every time I update my mail-client?

It takes the better part of 5 minutes every time (I'm not exaggerating here) and last year I had to do it twice!