First of all, don't panic. Don't do the ridiculous things that others have suggested, such as wiping your computer.
I have received those emails before and I have never lost any BTC from my Blockchain.info wallet. It may have been a phishing email. I have definitely received those. I hope you didn't click on any of the links in the email.
it wasnt phisihing email,
whatever i do what i want to do from the response from forum and from my friends , also the bc.info is down atm.