I've seen a few scams in my time, but I think this is absolutely 100 per cent legit, even though it took them the best part of three months to track me down and tell me I had won.
But Google, eh? What do they know about finding stuff?
Also, I am indebted to Barclays Bank for this timely email warning:
Thank you for writing, Barclays Bankers!* The exclamation mark shows that you are the real thing, because scammers don't use punctuation.
*NOT rhyming slang