I would like to prevent some of the junior users from sending to firstname.lastname@example.org. Is it at all possible?
Reasoning is that, typically someone will think its a good idea to send something to "everybody" when in fact they are actually spamming due to ignorance.
Even if it is possible, which I doubt, to remove the everybody group, I do not want to do that because then it prevents legit mails from management or HR.
So the question is. Is it at all possible to remove a user or group of users from SENDING to everybody on the domain?