Hi there,
It is the new security policy by Microsoft.
You will now be alerted when a message is delivered, only when it is determined with a high degree of confidence that it is phishing or malware, to a mailbox because of a policy that was enabled/disabled.
The alert policies will be enabled by default but you can turn them on/off as needed. You will also have the ability to define who gets the alerts and also manage how many alerts are sent to help control false positives.
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