Forum Discussion
Users are flooded with NDR emails (GraphTransactionItem)
Hello! We desperately need help in determining where thousands of NDR emails are coming from. This is Exchange Online only, not a hybrid deployment. About a month ago all mailboxes on one of the do...
Same for me. I made a ticket with Microsoft, and they ultimately said, "It came from you, it's your problem". They still come through every once in awhile. Mine sends to like 7 people or so, and it's always the same people. Don't know what the correlation is though.
Have you tried this?
https://social.technet.microsoft.com/wiki/contents/articles/30431.new-boomerang-feature-in-eop-to-prevent-backscatter-reverse-ndr-attack.aspx