A transport connection failed because the destination host was down. For example, mail delivery was attempted over several days, but the destination machine was not available during any of these attempts.
Report this error to the system administrator for the host. If you are the person responsible for this system, check to see if the machine needs repair or rebooting.
This error results from status information delivered by the underlying communication interface. If there is no known connection to the host, a different message usually results. For details, refer to "No route to host".
The symbolic name for this error is EHOSTDOWN, errno=147.