Q: How to set up e-mail server lists on server 3.1.2?

I have set up on an earlier mac mini some e-mail server lists that I need to set up on this new server. I lost the root pass word on the old machine and had to reset it then lost access to needed functionality on the lists for new lists. So I don't want to just set up from that old machine in case the error gets transferred over.

I'd like to just do it manually. I suspect I need to reset the root password on the new machine (as its not the admin password) but need the process.

I've read that postfix is already installed on the server 3.1.2 but how do I get to set it up and then set up e-mail server lists?