Can you help me to solve the problem we are encountering regarding the error on the next hop domain " SMTP Relay to Remote Acrive directory site" with error message " (451 4.4.0 DNS query failed. SMTPSEND.DNS.NonExistendDomain)"?
This is our scenario we have two active directory site for our organization the primary site A and the secondary site B. Our replication scenario is ACTIVE-PASSIVE, all mail flow should pass on the primary site. Both site has MX Record primary site has the highest priority while the secondary is the least. Our problem is if the primary site internet is busy and cannot respond immediately the next MX respond so the email will pass through secondary site and thats we encounter the error above. We already adjust all receive connectors.
Any idea on this?