That is an obvious epitome of when it seems too good sugarcoated, it is necessary to make research for validation.

Honestly the email seems fishy with how it emblems just an official notification as reminder of your registration to their gambling site.

It also seems your device has a defensive software that detects malicious domains which is why you have earlier been warned of scam.
So just give yourself that privilege of scam free and stay off the gambling site since you are not sure of haven registered in the site.