How to disable SSL in postfix

Dear Friends:

First I've to request apologizes about my bad English. I hope you understand my question.

I've followed the guide to configure Postfix, mysql and dovecot using an SSL certificate in Ubuntu 10.04, and it worked like a charm.

The problem is that I have a lot of customers that use "windows live mail", and when live mail is autenticating (only with smtp, I think), an anoying message appears again and again:

"the server you are connected to is using a security certificate that cannot be verified (…)"

There is no way to configure live mail to not show this message.

What I want to do is to disable SSL security in postfix, but I'm a newbie and don't know how.

Maybe you can give me an advice? I can post the postfix configuration file if ithelps.

Thank you in advance.

Cylon.