title: Apple Push Notification Response IP address
body: <p>I've been looking for an answer everywhere to no avail. I've developed an app for a client. This client works with money online so he has great security on his servers and the normal security policies, one of these policies is restricting external connections from domains, so the only way to register connections is by specific IP addresses. My problem is that the framework responsible of sending push notifications waits for an answer from the server to know if the push notification was delivered to a user, if the server response timeouts or the response says the notification was undelivered, the framework tries to send that notification again. This process is tried three times and after the third the framework doesn't even check for delivery status anymore and keeps working on the rest of notifications. The problem is that apple responses come from different IPs and if the IP responding is not one of the IPs registered on the client's security policy, the final user will receive three push notifications instead of just one. </p>
  
  <p>I`ve been trying to get the IPs by trial and error but it is frustrating and I've got more than 30 different IPs so far. Is there any documentation of the IPs Apple uses to respond to push notifications? Has anyone got a list of IPs by any other means?</p>
  
  <p>Sorry for the long post.</p>