Yeah not best title for topic I know

But got question folks maybe someone experienced such thing as well, on my old mail which i was using for beta access to ESO, before game went live, I receive letter:
"Greetings David,
Thank you for participating in our Welcome Back Weekend! We hope you enjoyed your time in Tamriel! and so on bla bla bla"
I didn't participated in this "welcome back weekend", never planned too, also didn't given key (if there was such) to anyone as well as account info, only I have access to mail (I hope so). And question is, everyone receive such mail despites of participating/not, or its just me and makes sense that my email get hacked and i need to change passwords and so on there?
P.S. I'm using other email for live game since pre-order.