Non-delivery reports are messages sent to a sender when a delivery attempt fails. Non-delivery reports can be disabled within email routing configuration policies.
You can select All to disable all non-delivery reports or Invalid Recipient to disable non-delivery reports for messages rejected by the destination server with the reason of invalid recipient.
Note
Disabling non-delivery reports is available for inbound inline and Inline with Hygiene domains only.
To disable non-delivery reports:
Select Configuration > Policies.
Create an email routing configuration policy or select a policy.
Within the policy's page, select Manage next to Email Routing Configuration. The Email Routing page opens.
Under Disable Non-Delivery Report, select All or Invalid Recipients from the Disable Non-Delivery Report for drop-down.
Note
The default is None. All non-delivery reports are enabled.
Click Save.