Thank you again for your response.
Instead of moving the IP to a new ISP, you might be able to change the dns record of your domain name to a new server / virtual server with new ip which is reachable on port 25.
Wasn't really sure how to point to a new virtual server so I went with a new ISP and got a new static IP address. The previous IP address was dynamic but it hadn't changed since I first got the service 2 years ago.
I figured I don't yet have all that many sites and I would just change them all manually.
OK, new ISP service up and running and I obviously can access the internet and I'm doing so thru my same old router. Didn't even need a modem, just ran the rs232 cable straight to the router and I was good to go.
But now ISPConfig won't respond @ server.example.tld:8080. Was it because I changed from dynamic to static IP and server network doesn't know?
Thank you once again for your assistance.