How has someone got your email address? Have you provided it to someone via PM?
OP shared screenshot of his email correspondance with sportsbet and his email address is visible there so I guess that's why he got that email. And yeah, I agree it looks very suspicious, most likely a scam attempt when they will ask for some kind of deposit to "unlock" the funds, or something along those lines.
Yes he is asking me for 10% of my balance to unfreeze my balance and send it to me. This sounds dodgy? Can anyone confirm this is real