MSMQ uses up to six system queues. All six system queues are implemented as private queues. Each queue and its use is described in the following table.
Table 1.1
| System Queue | Use |
| admin_queue$ | Storing administrative messages (such as test messages) |
| explorer_response_queue | Storing administrative response messages (except MQPing response messages) |
| mqping response | Storing returned MQPing requests |
| mqis_queue$ | Storing MQIS replication messages |
| notify_queue$ | Storing notification messages. These messages inform a computer about a change in its properties or a change to one of its queues (including creation and deletion of queues). |
| order_queue$ | Tracking transactional messages that require in-order-delivery |
The MSMQ system queues are not affected by a computer's message quota.
System queues cannot be deleted. Those users with Administrative privileges on their local computer have full control of the system queues on their computer except the Delete permission. Everyone has Get Properties, Get Security, and Send permission for system queues.