I only wonder why you provided them your email address which matters. I never do such things and use for casinos one of my numerous "anonymous" emails which I almost never check. ( Rare checks commonly resulted in deletion of all content in all boxes (no matter whether it is a spam one or some others). The letter you have received is certainly the fishing one. I'm sure the most casinos' data bases are already leaked.
Your reply is off-topic. I doubt that the OP or any other user who also mentioned here that they are receiving similar emails (including myself) have provided them with our email address. These are simple scam or phishing attempts, and the emails were likely acquired from database leaks (check haveibeenpwned to see some of the most major ones) through the hacked websites or emailing lists from the darknet. No one in the right mind would sign up for any kind of sketchy service that would address you as "beneficiary.".