we have one exchange 2003 server mail.example.com sending out and receiving mail. In DNS we have only on MX record 10 pointing to mail.example.com. We have know a backup mx record mail.isp.com (20) on our request, but it seems not to work. I get the impression that no mail will be queued or passed via mail.isp.com. Do we need to adapt or add some configuration to our Exchange 2003 environment?