Whatever happened to hosting your signature as an image at cutepersonalizedname[.]com and logging the IPs yourself? It probably wouldn't take much work to use

Whatever happened to hosting your signature as an image at cutepersonalizedname[.]com and logging the IPs yourself? It probably wouldn't take much work to use Automator.app to periodically uniquify the src URL in your sig and map Sent Item => unique hash into a sqlite database, later asynchronously updating it with IPs seen from an nginx server hosting your image. Presto, you're a "superhuman".