Is there a way to prevent a subscriber from replying is a VM sent via a private or public DL? We wish to allow administration to send a VM to a DL of students. However, we don't want the students to be able to reply. This is a 4.0(4) install.
Assuming you are integrating with an Exchange message store, there are Distribution List properties that will allow only specified users to send to the selected Distribution List.
See the MS article regarding mail storms below. The information provided is related to Exchange 5.5, but the same properties exist for later versions of Exchange: