I have the following scenario. We have an Exchange 2010 server. There's a specific group of users (around 200 of them!) on this Exchange server that we would like to have their emails sent to quarantine for reviewing before permitting them to be sent out externally. They are permitted to send emails internally within the organisation, but anything that's not part of our normal domains then we want that to be quarantined...not blocked. The reason being is these groups work at a variety of our stores and so due to confidential information, we can't let anyone just email people externally without us seeing what the destination email address is.
Is this possible on Exchange 2010 at all?