Troubleshooting Tip: How to troubleshoot FortiMail SMTP next hop relay error: 125Operation canceled

1. Navigate under Domain & User -> Domain -> Domain.
2. Select the relevant problematic Domain FDQN.
3. Select 'Test...' to perform Relay Host Test.

4. Navigate to System -> Utility -> Traffic Capture.

    

5. Select the '+New' button.

    

   

    

    

6. Fill up all the IPs that can be resolved under the Domain FDQN into IP/Host.

    

7. Select Create to start the capture.

    

8. Repeat Steps 1-3 to initiate a connection from FortiMail to generate traffic.

    

9. Select Stop to stop the packet capture.

    

   

    

    

10. Select Export to download the packet capture.

     

11. Submit to FortiCare ticket for TAC review.

     

The example shows that the result of packet capture indicates that 172.16.0.4 keeps sending a SYN packet and never gets a response from the far end.