what happens if email is mislabeled as phishing

In Outlook on the web, when a message is identified as phishing, Outlook treats it as junk and moves it out of the Inbox into junk-related handling so it does not appear as a normal message. Phishing detection in Outlook uses features such as spoof intelligence in Exchange Online Protection to verify the sender and mark malicious messages as junk email.

If a message is suspicious but not deemed malicious, Outlook marks the sender as unverified (for example, showing a ? in the sender image or a “via” tag) instead of fully classifying it as phishing, so it remains visible but clearly flagged as suspicious.

References:

• Phishing and suspicious behavior in Outlook
• Protect yourself from phishing
• How to protect against phishing attacks