Simple Message Queue (SMQ, formerly MNS) uses a dead-letter queue to store messages that are negatively acknowledged by consumers or for which all retries fail. This helps locate and process errors occur during the consumption of a message.
Dead-letter policy
Dead-letter status
If the maximum number of retries is reached, the message is dead-lettered and stored to the dead-letter queue.
Rules for saving dead-letter messages
You cannot select the same queue as its own dead-letter queue when creating one.
The message retention period remains unchanged after a message is sent to the dead-letter queue and is equal to the total duration during which the message is stored in the source queue and the dead-letter queue.
Create a dead-letter queue
Log on to the SMQ console.
In the left-side navigation pane, choose Queue Model > Queues.
In the top navigation bar, select a region.
On the Queues page, click Create Queue.
In the Create Queue panel, enable the Enable Dead-letter option in the Dead-letter Policy section, select the appropriate queue as the Dead-letter Queue, specify the Maximum Number of Times for Message Receiving, and then click OK.
For information on configuring additional parameters, see Manage queues in the console.