| Details | |
| Product: | Exchange |
| Event ID: | 577 |
| Source: | MSExchangeTransport |
| Version: | 6.5.0000.0 |
| Message: | Routing has reported the domain ‘%1’ as unreachable. The error is ‘%2’. |
| Explanation | |
| Routing cannot find a functioning next-hop. | |
| User Action | |
| At some point of time in the past Exchange failed to deliver to the next-hop and routing marked the link as currently-unreachable. Look for other events in the log indicating problems delivering in the past. If the problem persists, restart the SMTP Virtual Server and note which queue goes to retry. Highlight the queue and note the reason specified. | |