You are building a sales application using multiple Azure cloud services for orders, billing, payments, inventory, and shipping. The services need to exchange transaction information asynchronously using XML messages. Which Azure service should you include in your recommendation?

Azure Queue Storage is the correct choice because it provides a robust, scalable, and durable messaging solution for asynchronous communication between services. Its FIFO (First-In, First-Out) message delivery ensures ordered processing, and its ability to store large numbers of messages makes it ideal for handling transaction information like XML messages between decoupled services in a sales application. Azure Notification Hubs are for sending push notifications to various platforms, not for internal service-to-service messaging. Azure Blob Storage is designed for storing large amounts of unstructured object data, like images or documents, not for message queuing. Azure Application Gateway is a web traffic load balancer that manages and routes HTTP requests, not an asynchronous messaging service.