This article shows Operation images of email approval and attached files encryption in HENNGE Email DLP.
Emails can't be sent to outside unless a supervisor approves them if such a rule is set in HENNGE Email DLP admin console. Also, attached files in email are automatically encrypted if that setting is done in admin console.
The following movie shows how emails are sent to outside after supervisor approval and attached files are automatically encrypted. (This movie is Microsoft365 case.)