Microsoft Defender for Office365 incidents

Hi All,

We do have Microsoft Defender for Office365 Plan 2. We had an incident yesterday. the email was sent to group of people. the report status was removed after delivery. we can see Threat protection status reports and number of emails coming. But...

1-How can I know who opened the email?

2-How can I know who clicked on the link? as I already checked URL protection report and there was nothing there

3-How can I know who downloaded or opened the file?

Please advise

Thank you