sender is our own mailbox

Summary:

Our agents often forward an incident to one of our aliases that routes back to OSC instead of putting it in the proper queue. I know these are rightfully blocked as "sender is our own mailbox". This is a process training issue and I continually instruct users not to do this, provide them with a list of queues, etc. Do others have this same problem? Is there a better way of stopping this? I wish I could restrict them from sending to certain addresses or at least pop up a message if try to