|Example OU setup|
Recently I was tasked with figuring out a way to limit our student accounts from being able to send emails out to a large portion of our mailing lists/groups. The first option, blocking all emails except from owners and managers of the groups worked out great! Except they were the only users that could email those lists. Not a great fit, but do-able.
After some poking around and reading up a bit more on the control panel, I was able to get the settings figured out to allow all of our staff to email all of our mailing lists including the student lists (which were locked down from the first option as a band-aid fix), while blocking the students from emailing lists we specified.