We currently seem to only treat 410 Unregistered as an error that leads to a rejection making its way back to the homeserver.
However, perhaps we should also reject on DeviceTokenNotForTopic and some more (which we need to decide).
The consideration here is that we should only reject when an error is not Sygnal's fault and is permanent (since the homeserver will delete that pushkey once it's rejected).
See https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/handling_notification_responses_from_apns for a list of error codes.
We currently seem to only treat
410 Unregisteredas an error that leads to a rejection making its way back to the homeserver.However, perhaps we should also reject on
DeviceTokenNotForTopicand some more (which we need to decide).The consideration here is that we should only reject when an error is not Sygnal's fault and is permanent (since the homeserver will delete that pushkey once it's rejected).