When Unity systems share an Exchange server distribution lists are global. So a d-list created on Unity A will be propagated to Unity B and vis-versa.
each Unity has three built in D-Lists: allsubscribers, unaddressedmessages and systemeventmessages. These are marked as undeletable on the system they were created on and the SA won't allow them to be deleted.
Why is it that I can go to Unity System B and delete the allsubscribers D-List from Unity System A?