Notification email bouncing

Hello Vanan,

Thank you for contacting the Sophos Community!

Does the smtpd_main.log says anything?

Regards,

Hi Vanan Services,

Did you configure email protection on your firewall? If you are not using email protection on your firewall, disable the default SMTP/SMTPS rule. 

If the above is not true, provide smtpd_mail.log in debugging. 

SSH to the XG firewall: Sophos XG Firewall: How to SSH to the firewall using PuTTY utility

Run the following command from Advanced Shell to put the smtpd service in debug: service smtpd:debug -ds nosync 

Note: Run the same command to remove smtpd service from the debugging. 

Replicate the issue and collect smtpd_main.log. 

Check out the following KBA for more detail on log files: Sophos XG Firewall: Where to find log files?

Thanks,