How to allow email instead of just release when using shared mailboxes

I don't wish to have a customer end user to have to login to Central as an admin to have to release and allow emails from quarantine for shared mailboxes.  I did a web search and found nothing about how end users can accomplish this.  

Please help me understand how to instruct end users on how to allow emails that are caught in quarantine for shared mailboxes.

Thanks.