ISPConfig3 on debian lenny:Manual Guide

[deco5003]

I just have finished the installation of a Debian Lenny 5.04 Server with ISPConfig3. Now I got access from the internal Network to de control panel with http://192.168.1.100:8080, also I got access to Phpmyadmin MYsql and a PHP info page on www document Root. Also I have access to FTP services. Now I need to setup and configure the Mail Server. And setup the Internet access for that Server, not just from the internal Network. I guess by http://dec1.deccom.com I know that this can be done with ISPConfig3 Control Panel, but I couldn’t find any guide or manual for that task, Can any one help?
Thanks