NDR not received when sending from an Office 365 group

Brass Contributor

My client regularly sends email from an Office 365 group, i.e. they have "Send As" permissions against the Office 365 group in Exchange. Couple of screenshots below. Then they add the name of the group in the From box. Works fine.


However, they have asked why they don't receive NDR reports?


If they send the same email to a bad domain from their own account, they do get the NDR back.


Any ideas?




6 Replies

Hi @rob_nicholson_helios 


Just tested this out myself - looks like the office365 group mailbox sets up a rule to automatically delete any NDR's it receives:




That's why nothing is received back. I'm probably being a bit stupid, but I'm struggling to find and amend the mailbox rule for the O365 group either in the GUI or in Powershell. Just tried a quick mail flow rule to redirect automatic elsewhere, but it wouldn't allow it. Going to still have a play around with it for a bit.

Well, haven't found a way to edit the Office 365 group mailbox, but have found that giving users send-on-behalf permissions rather than send-as generates a NDR.

Thanks for this - at least one now knows why the difference between personal and send-as routes.
Unfortunately, I don't think they want the "On behalf of" tag adding to the emails. I'll check though.

Thanks for finding this issue and discovering what's going on with message traces etc. To get it some visibility (and hopefully have Microsoft fix the problem), I wrote the problem up in https://office365itpros.com/2019/09/26/office-365-groups-ndr-oddity/ and have sent it to some folks in Microsoft who might be able to persuade some engineering effort to happen. Don't expect an earlt fix though. These things take time.

Thanks @TonyRedmond, great write up.