BT have been contacted and confirm the below email is a scam, do NOT review your account via this email.
BT-based scams are becoming commonplace these days as the company is the largest UK telephone services provider. The aim of the scammers is to get your account details so that they can go to town on your money. They will try that by seeking details of your phone account or your Internet account.
This office has had multiple callers claiming to be from BT recently, including one more imaginative one where they said that a new router was being delivered at 10am the next day. Then they asked if the computer was turned on… Our response was to say that we’ll deal with the new router when it arrives, and put the phone down. Needless to say, there was no such new router delivered.