When calling this URL from our server, some requests are failing with 503:
https://buy.itunes.apple.com/verifyReceipt
> 503 Service Unavailable
> The server cannot handle the request (because it is overloaded or down for maintenance). Generally, this is a temporary state.
This is only happening to a small sample of our users, so my guess is that only some servers on Apple side are impacted...?