Use Office 365 DLP Policies to Block External Access to Sensitive Documents

 

When you need to block external access to your most sensitive documents, Office 365 Data Loss Prevention policies and sensitivity labels combine to find and protect the documents. A really simple policy is enough to detect and block external access, and is covered by Office 365 E3 licenses. If you have E5 licenses, you can consider auto-label policies to find and protect sensitive documents at scale.

 

https://office365itpros.com/2020/07/06/data-loss-prevention-with-sensitivity-labels/