Gents,
The thing about XMPP is that the ecosystem is probably 2 - 3 orders of
magnitude smaller than that of SMTP, and there are some very big players
that can help move things along, like Google, FB, to name two. With
SMTP, there are tens of thousands of MTAs, and that means that red flag
days along the lines of what Peter made happen (!!) gets harder to do.
Also, I would be curious of how often a crypto set failure happens with
email, given how much old software would linger. Would people care?
IMHO that makes you both right ;-)
Eliot