Configure Azure Service Bus MaxDeliveryCount and inspect the dead-letter sub-queue for a queue or subscription

Steps

1. Set the MaxDeliveryCount property on the queue or subscription (default is 10; valid range is 1 to 2147483647) at creation or via an update operation
2. Understand that each time a peek-locked message is explicitly abandoned or its lock expires without completion, the message's delivery count increments
3. Once delivery count exceeds MaxDeliveryCount, Service Bus automatically moves the message to the entity's dead-letter sub-queue with a dead-letter reason of MaxDeliveryCountExceeded
4. Access the dead-letter sub-queue directly using the path syntax <queue-path>/$deadletterqueue for queues, or <topic-path>/Subscriptions/<subscription-name>/$deadletterqueue for subscriptions
5. Inspect dead-lettered messages using a client/tool such as Service Bus Explorer, the Azure CLI, or an SDK receiver pointed at the DLQ sub-queue path, and read the DeadLetterReason/DeadLetterErrorDescription properties
6. Build a reprocessing or alerting pipeline that periodically drains and inspects the DLQ rather than letting it grow unbounded