Exchange 5.5 can't send mail to a sepecial another mail system
Posted on 2004-03-22
Exchange 5.5 on WinNT 4.0 BDC, it have a private IP address 10.1.1.2 and Public IP address 126.96.36.199 configured on a same NIC, the server located at DMZ port of a firewall, it's ok before last week and we didn't modify anything, but last Monday it suddenly can't send mail to a sepecial another mail system nipponexpress.co.th, we check the DNS service, run "nslookup -q=mx nipponexpress.co.th", respond is right, all mail send to this domain accumulated in the queue of outbound of internet mail connector, after 20 mins they are withdrawaled!
We don't know what's wrong with it , help us!!!