Queue Viewer is a utility in Exchange System Manager. It is used to maintain and administer messaging queues in an Exchange organization. The following are the queues that can be displayed in Queue Viewer from either a local computer or a remote computer:

1. An SMTP virtual server queue
2. A connector queue
3. A Microsoft Message Transfer Agent (MTA) queue
4. DNS messages pending submission
5. A failed message retry queue
6. Messages queued for deferred delivery

The Queue Viewer utility also provides the Disable Outbound Mail, Settings, and Find Messages options, and can be used to identify problems that need on-demand maintenance.