Law Firms adding new security feature to Microsoft Office 365 – Unverified Sender

Unverified sender is a new Office 365 feature that helps end users identify suspicious messages in their inbox. In order to help customers identify suspicious messages in their inbox, Microsoft added an indicator that demonstrates Office 365 spoof intelligence was unable to verify the sender.

To prevent phishing messages from reaching your mailbox, Outlook.com and Outlook on the web verify that the sender is who they say they are and mark suspicious messages as junk email.

https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/unverified-sender-feature