My key takeaway from here is to have a dedicated email for gambling related activities. I use more than one emails for different gambling sites and it is difficult to tracked where issues like this originates from.
It might be complicated to have different emails for different casinos except you have to record the details and keep them safe. But for me, it is better than having just one email if you can manage them. People who usually use one email in different casinos might have security issues in all the casino accounts if one account is compromised. A hacker or scammer can easily access other casino account if they have access to one. You can easily create many anonymous emails and dedicate each to a casino.
Creating several anonymous emails for security reasons is a good idea but also comes with its dangers too whereby you may not be able to access you account in situations where you are locked out and you don't have the details of the mail any longer since you didn't take cognizance of it because you didn't attach importance to it. in situations of forgotten password, that too could be challenging aswell and may lead to the you loosing the account and starting all over again to creating a new account.
having a dedicated email for gambling activities remains the best just like you have mentioned, that way you will be able to get control over you gambling activities from a single email without having to battle the stress of running around several emails and login details.