Don't worry about this email:
- It's an empty threat - the scammer is just using a well tried and tested approach to try to scare you into paying up. Actually they know nothing about you. Do an online search for "sextortion email scam" and you'll find lots of great advice and background information from security organisations about emails such as the one you have received.
- Although the email may appear to be sent from your old Virgin email account it is much more likely that the scammer has simply "spoofed" (faked) the address details to make it appear to come from your email account. That's standard with scams such as this and is just part of the scammer's tactics to try and convince you that they have access to you accounts or to your device.
Sadly, even deleting the old VM email account will not prevent the scammer from sending out emails that appear to have been sent from that account.
Having said that, it is still a good idea to get that old VM account deleted.
One of the Forum Team (VM staff who support this forum) can arrange that for you. One of the Team will contact you via this thread and take the details by Private Message.
Coenoby