Reject delegates a negatively acknowledgement through the Acknowledger interface.
When requeue is true, queue this message to be delivered to a consumer on a different channel. When requeue is false or the server is unable to queue this message, it will be dropped.
If you are batch processing deliveries, and your server supports it, prefer Delivery.Nack.
Either Delivery.Ack, Delivery.Reject or Delivery.Nack must be called for every delivery that is not automatically acknowledged.