Explain volatile queues and Dead letter queues.Volatile queues
WCF also uses non transactional queues for storing messages. Such queues are volatile in nature. They are stored in memory and not used in transactions. On shutting down the machine, the queue is lost. They don’t guarantee the transfer of messages.
Dead letter queues
Dead letter queues are used for failed or dead messages. When a message delivery fails, it is stored in a dead letter queue. MSMQ has two types of dead letter queues recording failed messages for transactional systems and non transactional systems.