Whenever i use my email address on a website, i always use it in this format: website@mydomain.com
And since half a year i get these blizzard-emails which are send to curse-gaming.com@mydomain.com and curse.com@mydomain.com
So that makes it pretty clear who sold it's customer database... (or had it's database stolen)

This also makes it very simple for me to see if it's a genuine blizzard email or not.