That's exactly it. Sign in on Apple TV with your us iTunes as you would for us netflix.How do you subscribe? Is it as simple as buying a US iTunes gift card, redeeming it on a US iTunes account and then signing up on Apple TV? I'm already using UnoTelly to watch US Netflix on Apple TV so I'm all sorted there.
I have a feeling those getting emails have accessed signed up via devices that aren't going through devices that access the net outside their geo blocking service.