I'm afaird I don't have any experience using UUCP so can't offer any advice with that.
You probably know all this but I think it bears repeating, make sure you have a valid and correct /etc/hosts file, valid DNS A & MX records in a
Split DNS set-up (if necessary) and if you have a Split DNS then your resolv.conf should only point to that DNS server.
If you have any questions about the config of those items then feel free to post again.