Once I really contacted one of this scammers. It was a much more clever mail than that you’ve received (but I don’t remember exactly the terms) and the promised amount was more realistic (around tens of thousands). They replied that all was set and I had only to pay a small amount for settling admin expenses (a very small amount, under $100) to proceed. I didn’t reply to this and they didn’t follow (they didn’t «push», to add realism).
I did for curiosity, of course, but I’m still wondering if someone really fell in the trap. I’m not sure, but I’d guess yes.