Listed below are the expected responses from the push endpoint:

• 200 OK - Message accepted by service.
• 401 DENIED - Service token/auth key denied
• 403 FORBIDDEN - User token cannot accept push notifications.
• 500 SERVER ERROR - Error in processing request

In case of a network error (5XX error code), messages are resent every 10 seconds for up to 4 attempts.

TLS errors behave according to TLS spec error codes.