Ok, I have figured it out somewhat. I made a file called mynetworks and included this line:
66.176.xxx.xxx <--- my friends IP
pompano.net <--- friends and my domain ( I think at least that is what it would be, as in my IP is something like suneast-176-xxx-xxx.pompano.net)
My question now is, which one of those lines is what needs to be there? I mean can I just manually add exact IPs for each person that wants to use my mail server?? Do I need the pompano.net line??