Recipient exception not working when it matches exactly.
Article ID: 277198
Data Loss Prevention Endpoint Prevent
A user or domain pattern appears to match exactly but is still not functioning in a policy.
Copy/paste functions can introduce unexpected characters into a policy that is not easily visible.
Export the policy and open it in a feature rich text editor such as Notepad++, you will likely need to enable the feature to show hidden characters.
Locate the non-functional pattern.
Search for any unexpected characters. In the example below some zero-width space characters was introduced into the user patterns. If any are identified, retype the affected sections of the policy and re-save the policy.