DLP Quarantine emails do not show up in the user email!

DLP Emails are only for the Admin Superadmin available. 

Thank you very much. With this DLP policy setting, does the user see the email back in quarantine?

Unfortunately, with the checkmark set, you will only receive a notification, but you will not be able to release and deliver the message.

That is correct. You can inform somebody but still the Admin is the only part to release such content. 

This is an expected behavior. Just think of DLP as something that is supposed to restrict information from getting in or out of a company and not as an anti-spam solution hence the name "data leakage prevention". The administrator explicitly set these policies as per each respective company's rules. If these DLP quarantined emails can be released by the users then it nullifies what the administrators have set.