eM license server address

I have several PC’s that are not internet facing for security reasons, that are running licensed versions of eM. We use them to communicate on our internal network only. Unfortunately, they have failed after 14 days because they cannot contact your update server. Would you please provide the I.P. address to your update server so that I can open a port through my firewall for those machines to reach your server? If you have any other suggestions, please advise. THANKS!