Certified MuleSoft Platform Integration Architect

A company is designing an integration Mule application that processes orders by submitting them to a back-end system for offline processing. Each order is received by the Mule application through an HTTPS POST and must be acknowledged immediately. After acknowledgment, the order must be submitted to a back-end system. Orders that cannot be submitted successfully because the back-end system rejects them must be handled manually (outside the back-end system).

The Mule application will be deployed to a customer-hosted runtime and can use an existing ActiveMQ broker if required. The ActiveMQ broker is located within the organization's firewall. The back-end system has a history of unreliability caused by both minor network-connectivity issues and longer outages.

What combination of Mule application components and ActiveMQ queues is required to ensure orders are automatically submitted to the back-end system while supporting, but minimizing, manual order processing?