The webhook calling code will attempt to deliver the message multiple times over a configurable period with back-off retry if it fails to get a 2xx response code. If the webhook surpasses the number of attempts that are allowable by its config then the webhook will be placed into an errored state and will not automatically attempt re-delivery. You can still ask for these webhooks to be retried via the /retry and /retry-all endpoints.
Retry attempt is configurable and the retry attempt is tracked at individual event level. The webhook system will mark the event as failed to deliver and stop sending them after all the retry attempts are exhausted. Individual event delivery failure does not have impact on the delivery of other event and webhook event type.
Webhook events which are failed to deliver will not be send any more. This is to avoid a situation when there is extended period of outage and webhook events are building up. To get the events which failed to deliver, use API to get the webhook events which are failed.