It's what's known as a 419 Scam ... it's an advance fee scam where they try to get you to pay a couple of thousand pounds in order to receive hundreds of thousands ...
If you Google 419 Scam and have a read ...
Also, the Metropolitan Police will be pleased to receive any emails you have ...
right-click on the email, select 'properties, then details, then the 'message source' button and 'cut & paste' the 'message source' contents into a new email, together with the original email text, with a quick note explaining it's a 419 scam ... they are genuinely pleased you can help them ...
email it to ...
[email protected]