Phishing mails are pretty much a constant menace and some are very convincing, the simplest advice is if you receive any e-mail about an account issue for Facebook, Paypal, bank etc. never click the link in the e-mail and instead go to the address bar and type in the website address yourself. If there is an account issue you'll be prompted about it when you log in but if the account is fine and the e-mail was fake there will be nothing.