How to ensure all the mails go through quarantine directory

==== Required information ====
- iRedMail version: 0.8.6
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: CentOS 6.x
- Related log if you're reporting an issue:
====

Hi,
      We would like to approve outgoing mails manually. So we are thinking of sending them to one quarantine folder. How can we see their contents through a browser and approve them manually? And, is there a better way of doing this?

Thanks