This is a known problem.
http://tools.ietf.org/html/draft-ietf-xmpp-dna-05#section-8 explains
that in more detail.
The currently proposed solutions for this are to either use DANE or
POSH.
Thanks. This is an answer.
This exact the headache I have at the moment.
The clients simply want email address and jabber id identical and please
everything somehow secure. How this is done: My problem, otherwise the
client would not ask somebody to provide this services for him and
operating everything himself.
And thanks pointing that I refereed an obsolete RFC.
Andreas
