Due to security policies, you can require your users to classify some or all emails. Or you can automatically enforce your policies. You can warn when the user selects an unsuitable tag and force them to make the right choice.
Enforces Policy
It makes the user’s classification of each message compatible with data classification policies without leaving it at his own discretion. You can use message classification to control who can send messages to whom, and configure classification permissions based on specific users, internal groups, or external domain structures.