Spam, or Ham?

Had a wonderful message in my Spam directory this morning.

It’s a message from this guy who says he is 

Mr. Paul Wolfenden, Manager of ABN AMRO BANK

250 Bishopsgate, London EC2M 4AA .

I have a business
proposal valued Twenty-One Million Pounds from my bank.

Please, get back to me to enable me furnish you with
more information concerning this letter.

Regards,

Paul Wolfenden.

Now what was the clue which told me that this was not a kosher communication from a reputable bank?