Microsoft 365 includes an email quarantine feature that blocks most spam and malicious email, but sometimes need a second set of eyes to verify if the email is indeed spam. In this scenario, you will receive an email from Microsoft (quarantine@messaging.microsoft.com) stating that the email needs to be reviewed before it is released. Steps on how to release are outlined below: Start by visiting the Quarantine center: https://security.microsoft.com/quarantine  Step 1: Verify the Quarantine alert is legitimate  -Valid Quarantine emails will only come from Microsoft using this email address: quarantine@messaging.microsoft.com -Email quarantine can also be checked by visiting this website, if you are not entirely sure if the email itself is valid: https://security.microsoft.com/quarantine -Clicking "Review" on the quarantine alert email will allow you to review why the message was quarantined and who it was from Step 2: Decide if the email is spam or legitimate  -Most often the messages in quarantine are indeed spam, in which case you can click "Block Sender" to never receive an email from that person again  -If you are confident the email is definitely not spam, click the "Release" button for the message to be sent to your inbox  -In case you are not sure, but want to get a closer look without releasing the email, click on "Review Message" to be sent to the Quarantine Center. Step 3: Making a final decision - Click on the suspicious email's subject from within the Quarantine Center  to make a final decision on whether to release the email  - Click "Release Email" if you are confident it has been marked incorrectly  - Click the ellipses (...) to expand the menu and Block the sender if they are indeed malicious   Click the ellipses (...) to expand the menu and click "Submit for Review" if you are still not sure