Hi Florian,
FWIW I asked whether MX should advertise TLS in this thread:
Date: Wed, 7 Nov 2007
Subject: [exim] Should MX offer TLS ?
http://www.exim.org/lurker/thread/20071107.001248.0ce88323.en.html
The advice from bigsite admins seemed to be you get bored of excluding
broken peers by /32, and therefore best turn off TLS for the MX.
(assuming, as Tony and Ian note, that client submission is separated off
by port or IP address or different machine etc)
The thread also discussed whether use of TLS might be a useful (non)-spam
indicator, which was fun...
