Resolution:
Generally, a , sometimes referred to as an undelivered-message queue, is a holding queue for messages that cannot be delivered to their destination queues.

In TIBCO EMS, if a message expires or has exceeded the value specified by the maxRedelivery property on a queue, the server checks the message's JMS_TIBCO_PRESERVE_UNDELIVERED property.

If JMS_TIBCO_PRESERVE_UNDELIVERED is set to true, the server moves the message to the undelivered message queue, $sys.undelivered; If JMS_TIBCO_PRESERVE_UNDELIVERED is set to false, the server will delete the message.

This undelivered message queue is a system queue that is always present and cannot be deleted.