By replying to the notification message

When an email incident is blocked, or indeed any policy breach is discovered, notifications are sent to all the users configured in Main > Policy Management > Policy Management > Resources > Notifications. Users can release email incident by replying to the notification message.

If the message was successfully released, the user who released the message receives a confirmation email.

See Releasing email blocked by Forcepoint DLP on the Forcepoint support site for information on configuring the release gateway and Microsoft Exchange or Active Directory settings.