Register Email v2.6 changes:
In Register Email v2.5 I was using geobytes.com for IP to location lookup, this turned out to be very inaccurate. So in Register Email v2.6 I switch to using geoplugin.net for IP location lookup.
Note that whatismyipaddress.com is still more accurate than geoplugin.net, but whatismyipaddress.com doesn't offer an API to retrieve the location based on IP input.