Retries and Callback Suspensions

Your Event Notification Service (ENS) callback has up to three seconds to process an event batch and return an HTTP 200, 201, 202, 203, or 204 response, indicating successful processing.

If the callback times out, is unavailable or unreachable, or returns an error code, the ENS tries to send the batch up to three times.

If the third attempt fails, the batch is deferred for up to 10 minutes, and the ENS tries to deliver the delayed events at decreasing intervals for up to seven days. After that, retries stop and delivery fails.

For deactivated subscriptions or callbacks, the ENS doesn’t attempt redelivery.