[exim] PHPNuke and EXIM4

Hello all, I am really new to Exim and I have a few questions that I
would like to ask. I have a web site that uses PHPNuke and this
community board like Exim when it is on a Linux box. I want to be able
to use Exim to send out emails to external sites. How can I do this, I
can only send mail to internal mail boxed on the server. If there is a
how to can you please send me a link.

Thanks
-T