Question
How can I check that the host computer is up and running and that the DNS is operating correctly?
Answer
If you are experiencing difficulties sending mail messages it is possible to verify what is happening by using the MAIL utility. Entering a command such as:
MAIL -m
will look up the MX records for specified server. The MX records specify the list of remote machines that will accept mail messages for the specified host. The MAIL command lists the servers together with the IP addresses.
If the MAIL command returns an error code, it may be because either a DNS server has not been set-up or has been incorrectly specified. Once the list of MX records has been obtained it is possible to Ping each of the servers in turn to see if they are reachable. Using an NT Command Prompt enter the command:
PING
If Ping returns with Destination host unreachable, then that server is either down or perhaps is no longer available. If the host was reachable, you need to check whether it is receiving mail.
See also: FAQ26: Is remote mail server running?
Keywords:mail server host test down MX records