"Send only one notification per incident" not working - getting 20 mails for 1 incident

Steel Contributor

Hi everyone,


we are using the mail alerts for opening tickets in our ticket system.

Every mail = one ticket


We have selected "Send only one notification per incident" for this.

But we are getting a mail for every alert in the incident.

This is one incident.



We can merge the tickets - but this has do be done manually and takes 5 seconds for each merge.


Is there any other place we might have set this?

At the moment i am looking at:Settings -> Microsoft 365 Defender -> Email notifications




3 Replies
best response confirmed by StephanGee (Steel Contributor)
Hi Stephan, not an expert here - but trying to help troubleshoot :)
I see that there are two places to set email notifications
Settings > for Microsoft 365 Defender
and Settings > Endpoints

Also in the settings for Microsoft 365 Defender you can specify the source of the alert, did you select all of them, or just Microsoft 365 Defender with the sub items?
I am wondering you somehow activated duplicated settings.
I can't see from your screenshot what the sources are, but are these all endpoint alerts?

@Heike Ritter 

I think this is it! We have it for alerts AND incidents :)

I disabled the alert rule for our shared mailbox - maybe this was it.



In this case it was an endpoint alert.

We did select all of them. 



Great, glad I could help :) I will also chat with the feature owners, to make these things more clear.