This question is concerning an Intel server running Redhat 9 and Plesk.
When Redhat was installed, the default "medium" firewall option was taken.
Now that plesk has been installed (to allow website hosting) - the server rejects connections for POP and SMTP - preventing people from checking mail (which resides on the server).
Just as an experiment, I stopped the iptables service. That allowed me to log in and get mail.
I do not want to completely do away with the protection of the firewall. Thus I only need to add allowance of inbound traffinc on the POP and SMTP related ports. I have read through the redhat manuals and am in way over my head at this point.
Can anyone provide advice on how to do this?