Withdrawal email is normal. But if you do not want to get the email again, you can go for the 2FA on the gambling site. Many gambling sites on this forum has 2FA feature.
The emails don't bother me. It helps me to see that everything is going smoothly when I request for withdrawal.
The reason I am using just one email is because I do not save my gambling site account password anywhere. I only click on forgot password to set another password and access the gambling site if I have forgotten the password. Having different emails for each gambling site will make this difficult for me because I can forget the email that I used to register on a gambling site.
Yea, this is another valid reason to use just one email address for all gambling related activities. Convenience and stress free. Unfortunately, I don't think I can change emails on the other gambling sites to just one. I'll do this on new gambling sites going forward.