All emails that match the criteria for quarantine will be sent here so that the admins and super admins can classify and choose the appropriate action. It's recommended to adjust the safety settings so that all suspicious email is sent here:

All newly quarantined messages will land in the All Quarantines tab. Super admins can create sub-categories for better manual classification using Manage quarantines. 

If you are using Chrome, you can create app-like direct access for this (or any other) part of the G Suite admin console by clicking  in the top-right corner of the browser, and then More tools, followed by Create shortcut, and changing the default name if you wish. Make sure that you have Open as window activated and then click Create:

Once an action is taken against a quarantined message, it will be filed either as Denied or Allowed. This will simplify the auditing and double-checking of security decisions and apply corrections if needed.