Is there any site at all running STARTTLS?

I was really excited, looking forward to installing and using
encrypted sendmail (smtps a.k.a. STARTTLS), but I couldn't find a site
that runs it -or so it seems.

I tried the command in the documentation:

% openssl s_client -starttls smtp -connect host:smtps

with several domains: ibm.com, sendmail.org, sendmail.com but none of
them seem to be listening on port 465.

I even tried this:

% host -t mxs ibm.com :-) but it doesn't work.

TIA,

-Ramon F Herrera