I received this today from someone I trust so I believe it's genuine. The "Nigerian Inheritance" people are getting more subtle.

Postal Scam:

Can you circulate this around especially as Xmas is fast approaching - it
has been confirmed by Royal Mail. The Trading Standards Office are making
people aware of the following scam:

A card is posted through your door from a company called PDS (Parcel
Delivery Service) suggesting that they were unable to deliver a parcel and
that you need to contact them on 0906 6611911 (a Premium rate number).

DO NOT call this number, as this is a mail scam originating from Belize .

If you call the number and you start to hear a recorded message you will
already have been billed £315 for the phone call.

If you do receive a card with these details, then please contact Royal Mail
Fraud on 020 7239 6655.

For more information, see the Crime Stoppers website:
Postal scam email from Parcel Delivery Service