App Or Widget That Informs Of IP Address Change

We have a couple of sites that have not yet implemented a static IP address with their ISP for their video system, even at our urging. I was wondering if anyone knows of a (malware free) app or widget that could be installed on the VMS to email when it's public IP address changes? Preferably freeware... Thanks!

Jason, if the VMS will accept a dynamic name this is exactly what DDNS would manage for you.

We have had good success with and their update client is very light with both Windows and Linux available. Also the client can be found in at least LTS (Hikvision OEM) recorders.