An order fulfillment system needs FIFO processing per OrderId, scheduled delivery of messages, automatic dead-lettering after 5 failed processing attempts, duplicate detection within 10 minutes, and the ability to atomically receive a message and publish two commands. Which messaging service should you choose?

Azure Service Bus Premium is the correct choice because it natively supports all the specified requirements. Sessions provide per-order FIFO (First-In, First-Out) processing by ensuring messages with the same session ID (e.g., OrderId) are processed sequentially. Scheduled delivery is a built-in feature. Automatic dead-lettering after a configurable number of delivery attempts is standard. Duplicate detection within a specified time window is also a core capability. Finally, Service Bus supports transactions, allowing atomic operations like receiving a message and publishing multiple commands within a single scope. Azure Storage Queues lack native support for sessions, scheduled messages, duplicate detection, and transactions. Azure Event Hubs is designed for high-throughput event ingestion, not complex message queuing with sessions or transactions. Azure Event Grid is primarily an event routing service, not a message broker with advanced queuing features. Azure Queue Storage with Durable Entities adds complexity to achieve ordering that Service Bus provides natively.