# Dead Letter Queues

* **If a message can't be consumed successfully**, you can send it to a dead-letter queue (DLQ).<br>
* Dead-letter queues **let you isolate problematic messages to determine why they are failing**.<br>
* The **`Maximum receives` value determines when a message will be sent to the DLQ**.<br>
* Dead-letter queues are **useful for debugging your application or messaging system**.

## How do dead-letter queues work?

* **Sometimes, messages can’t be processed** because of a variety of possible issues, such as erroneous conditions within the producer or consumer application.<br>
* For example, if a user places a **web order with a particular product ID, but the product ID is deleted, the web store's code fails** and displays an error, and the **message with the order request is sent to a dead-letter queue**.


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