The domain name 'btcustomers.com' is owned by a small American company, Skystream Technologies. That company, and the domain name, might be perfectly genuine. (i.e. 'BT' could mean something else in the USA, so there's nothing wrong with Skystream Technologies having the domain name).
However it's clearly nothing to do with our own 'BT', so the message is definitely a fake. (I suspect that the email address has simply been 'borrowed' by the hacker who has tried to get you to click on something nasty. Skystream Technologies would probably be horrified to hear that their domain name has been used in such a way).
Delete! Delete! Delete!