We are configuring exchange 2010 SP3 hybrid setup. when we try to send mail from office 365 user to on premises users get following error
How to fix this issue..???
Delivery has failed to these recipients or groups:
The domain name in the email address is incorrect. Check the email address.
Diagnostic information for administrators:
Generating server: HK2PR06MB0849.apcprd06.prod.outlook.com
Remote Server returned '554 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domain'