Forum Discussion
Limit or Moderate emails with multiple recipients in Office 365
I would start with Exchange transport rules as that allows you to perform the outcomes you're hoping to (ie. if mail comes for this recipient, send a copy to that recipient - or - if this person sends an email, redirect it to their manager for approval).
Have a look here: https://technet.microsoft.com/en-us/library/jj919238(v=exchg.150).aspx
There are many functionalities that can help you with that, but you need to be more specific - what exactly are you trying to achieve here? In addition to the transport rules as Loryan suggested below, you can impose delivery restrictions by leveraging the corresponding mailbox/group parameters, you can enable the actual "moderation" functionality, you can also take a look at the Supervision functionality: https://support.office.com/en-gb/article/configure-supervision-policies-for-your-organization-d14ae7c3-fcb0-4a03-967b-cbed861bb086
And more...