[Exim] exim & TLS

Hello

I have 2 question about TLS and exim

1) I have mail gateway and some domains. My base domain is: mail.x.pl
Any user with own domain have this line in domain zone:
mail IN CNAME mail.x.pl.

So, How i can sign ssl cert? what write as domain?
The M$ outlook always display warning message "cert & domain mismatch".

2) My ssl sesion of exim listen on 25 port. When client sent STARTTLS then connection is secured. Some M$ programs listen on secured ssmtp port. Is a exim have same settings on port 25 to 465?

I greet
Roxik