Problem : #5.4.0 X-Postfix; too many hops NDR being received from certain email addresses
When we try and email certain addresses, we get the error on a NDR below:
The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify the email address and retry. If that fails, contact your administrator.
It only happens to a small number of domains, and possibly only one.
Solution: #5.4.0 X-Postfix; too many hops NDR being received from certain email addresses
Have you tried increasing the hop counts on the default smtp virtual servers (delivery tab/advanced button/maximum hop count). We had similar problem with one domain . We increase our hop count to 25 and had no problems. Exchange 2003 defaults to 30. Exchange 2000 defaults to 20, i think.