IP addresses are sometimes changed at the network level. While network personnel almost always inform you when this happens, it is possible an address has changed.
If you get a message telling you your IP address is invalid, contact your network personnel and ask to verify all the external IP's for your site. If the IP addresses have changed, you should call Customer Service and we will update them in your account.
If your IP addresses have not changed, please fill out this support form. The support form will email us pertinent information about your account. We will verify your account settings and contact you directly regarding the problem.