Access your Quarantine to see a list of all emails available to be reviewed. This top-level view will show you general information such as the Sender or Subject, why the message was quarantined and if it has been released or not. It will also show an expiration date. Once the expiration date has been met, the message will be removed from quarantine regardless of whether it has been reviewed or not.
Each quarantined message will have a checkbox next to it. Selecting a message will open a window that will provide details of the message. Along the top of that box are several buttons. From there you can choose to Preview the message, allowing you to safely check the message to determine if you want it delivered to your Inbox or not. You will also have the option to Release the message, which will deliver it to your Inbox, or Remove from quarantine, which will permanently delete the message. Please note that emails removed from quarantine will not be recoverable.
Note: It is recommended to not use Internet Explorer to access the Quarantine. Internet Explorer does not seem to be well supported. Attempting to release quarantined emails from this browser has been seen to not work properly.