Urgent DNS Issue

[MarkITMan]

I have a server running MS Exchange and we have problems. I ran a diagnostic program and it says: " GUID Server name could not be resolved to an IP address. Then it says xyz.abc.com resolved to the IP address (123.45.67.123) and was pingable. The A and MX are registered in the server, but we still can't send e-mail because of the DNS issue. What are we missing here? ANy help would be greatly appreciated.

Thanks

 

[meekrob]

What diagnostic program? What is the issue in the first place? What is xyz.com (the address of the exchange server?)? Can you send internal mail? The MX record is set in what server?

Details. We can't help you without more info.