Messages in this queue cannot reach their final destination server. For example, Exchange cannot determine a route or a connector to the final destination, or all available routes or connectors are marked as down.
Messages can accumulate in this queue if no route exists for message delivery. Also, if an Exchange connector or a remote delivery queue is unavailable or if it is in a retry status for a while, and no alternative available route exists to the connector or the remote destination, new messages may be moved to this queue. The administrator can then address the problem or define an alternative route. Use the WinRoute tool to help determine available routes and route status.
To troubleshoot the queue that is causing this issue, restart the SMTP Virtual Server to reset the connector status and to retry the messages that are queued. To restart the SMTP virtual server, follow these steps:
- Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
- Expand the Servers container, expand your Exchange Server computer, expand Protocols, and then expand SMTP.
- Right-click the SMTP virtual server, and then click Stop.
- Right-click the SMTP virtual server again, and then click Start.