kumomta/docs/reference/kumo/make_queue_config/max_retry_interval.md

max_retry_interval

Messages are retried using an exponential backoff as described under retry_interval below. max_retry_interval sets an upper bound on the amount of time between delivery attempts.

The default is that there is no upper limit.

The value is expressed in seconds.

kumo.on('get_queue_config', function(domain, tenant, campaign, routing_domain)
  return kumo.make_queue_config {
    -- Retry at most every hour
    max_retry_interval = '1 hour',
  }
end)