For the past few minutes, I've been repeatedly receiving Microsoft 365 Defender threat analytics report emails—34 messages in about two minutes. Is anyone else seeing the same burst of notifications? Update: the emails stopped shortly after I posted this.
5 Answers
Before treating the messages as a service issue, verify that they’re genuine. Check the sender details and whether the messages pass SPF, DKIM, and DMARC. A similar-looking email could also be phishing or ordinary spam.
Yes, we saw the same thing here—an unusually large burst of Defender notifications.
We got roughly 34 reports as well. It appears to have stopped for now, though I’m keeping an eye on it in case another wave comes through.
I’d monitor it for the rest of the day. If the notifications start flooding in again, temporarily disabling the affected report subscription may be the quickest way to quiet the alerts while the issue is investigated.
Same on our end. We received a whole pile of notifications within a very short time.

Ours stopped too, almost immediately. Hopefully the backlog has fully cleared.