Honestly I don't care with my mail because it's full of spam, even my personal email is full of spam too, I have no idea how can someone find my personal email. I might miss some important mail, but usually people who seek me not only send message to my mail, instead they also try to contact on my telegram or Whatsapp.
The entire concept behind cryptocurrency has to do with anonymity and I do not think that any crypto casino that really understand what cryptocurrency is will like to adopt the habit of regularly sending emails to customers as that can become a disturbance.
Nah, even Bitcoin is just a pseudonymous coin, only some coins are focus in anonymity, the rest are centralized and contain KYC. And I think most of cryptocurrency are sending spam email to because they ask you to subscribe their emails.