We are a school district and need to prevent to our students from being able to receive email from outside our district.
IE, no internet mail.
I am already aware of the "users must be authenticated" trick but I know there is a better way to do it. We set it up for our Exchange 2010 server years ago but I can't remember how. Our students now do not have the "users must be authenticated" checkbox checked, and do not receive external email so I know it can be done another way.
If I remember right we might have done it in Exchange 2010 with the anti-malware somehow?
