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As of the option is also available from shared mailbox where you have the right to send from it ( send as or send on behalf), not where you only have read access
In Outlook
Open the mail in outlook (at least in the read panel)
A button is available in your toolbar: "the report message". Click on it
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What we do with what you flag?
If you report it, we will review it and confirm the junk/phishing attempt.
If it’s a phishing attempt, we can then directly block similar email, attachment, or URL to avoid any issue for other user.
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