Yes, you can change the IP address of a server running Alligate. There is only one thing to watch for when changing IPs. If you have Alligate bound to a specific IP address, you need to change it to "All" before making the IP address change. You can do this in Network Connection Options area in Alligate under Bind SMTP Server To Address. After that is done, you can bind it to a new specific IP address if you need to.