NDR not sent to let user know the message failed to be delivered

Question

We are using Sophos Gateway and routing email out of Microsoft 365 through a Sophos Smarthost. When a user sends an email that fails to be delivered due to the recipient address being misspelled or the recipient not existing the senders never receive an NDR. Sophos shows the message as failed along with the reason that was reported from the recipient server. Is there a setting to allow Sophos to pass the NDR from the recipient server back to the sender or am I missing something else?

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Tom Foucha · Accepted Answer

This is something that is on our roadmap for delivery in the near term. We will deliver these NDR's via an IP pool similar to what Microsoft does. Purposely we've protected our IP space by not sending NDR's as many are generated by attackers and can impact your IP space reputation.

Tom Foucha · Answer

This has been rolled out to customers and if NDR's aren't being delivered please open a support ticket so we can investigate., Thanks-Tom

NDR not sent to let user know the message failed to be delivered

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