public MessageDeliveryMode getDeliveryMode(MessageDeliveryMode defaultValue) {
			String deliveryMode = getProperty(DELIVERY_MODE);
			if (StringUtils.hasText(deliveryMode)) {
				return MessageDeliveryMode.valueOf(deliveryMode);
			}
			else {
				return defaultValue;
			}
		}
Whether to automatically declare the DLQ and bind it to the bus DLX.
spring-xd-messagebus-rabbit/src/main/java/org/springframework/xd/dirt/integration/rabbit/RabbitMessageBus.java