Of course insurance companies want to use every signal available to them to price discriminate on rates. If you are a good driver, the insurance company wants you because you are unlikely to file claims. Likewise, you are happy to receive a discount for being a good driver. A simple signal of being a good driver is your driving record, but we all know this isn't very reliable by itself. So you end up with other signals being used. Literally any signal that is not protected (like race/gender) will get used in any insurance model. None of this is new. The color of your car is used surely, so why is it so shocking that your email domain is used as well?