in alot of cases, if you notice the email address of the sender once you open it, you can pretty much tell that its coming from a spamming affiliate, which is ridiculous to promote any good casino that way.
Not only does it bug the hell out of the receiver, make the casino look bad for looking like they are sending them out, But also makes all affiliates look bad as well, and that ashame that some may feel that way because of these spamming affiliates.
Just next time when you know you got a real email from a casino, take notice of their email addy and then they next time you suspect one being spam, take notice of their email. you will notice some of these spammers do alot to make it look like the email is coming from the casino.