Block student to student email for specific user

[ParatrooperJoe]

Our Middle School Principal is wanting us to set up a sort of penalty Box where we can put students in, and they can not send to or receive from the student email domain, but can continue to send to and receive from the staff domain.  As an example, our staff uses  @ourdomain.org while the students use @ourdomainfulllength.org

The preferable method would be to put the penalized student into a PenaltyBox group that is configured in a way that the student can not send or receive emails to @ourdomainfulllength.org, but they can continue to receive/send emails from/to @ourdomain.org.  If this is not possible to be done by putting them in a group, then perhaps an OU that has some specific settings to achieve the above?  It would just be way easier to do it by group, of course if I knew how to accomplish it, lol .  Open to ideas on this. Thanks in advance!

[ParatrooperJoe]

ll, I actually figured out how to do it via setting up a sub OU, and setting email compliance rule to only allow send/receive for teacher/staff domain, and moved that student into that OU. Tested and it seems to work. 

If the Penalized student account emails another student, the email seems to never get sent, (not even a trace of it in the Vault), and despite there being a reject message, the student does not get notified that their email did not go through. This does achieve the end goal (so it seems with my small testing) but it would be easier if could set up that same scenario with a group, as opposed to having to move the student into that penalty box.

[ParatrooperJoe]

a bit more testing has revealed that the reject message (for my particular setup) appears to be displayed to a student who tries to email a student who is in the email penalty box ou.  Good to know.

[Kim_Nilsson]

Not all things can be set by group. Routing and Content Compliance rules are such things.

The issue is that the group membership isn't checked when an email is sent/received.

But, it never hurts to give Google feedback on that, so it can perhaps be added in the future.