Adding feature to existing Simple Windows Form Application

I have this simple software made with windows form in Visual Basic with .mdb database. It is an inventory issue tracker. If we have issue with inventory we create case in issue tracker, there are 2 departments involved in the interaction manager and warehouse personnel. When manager enters the issue – the warehouse guy can see the open issue in a grid view (Let’s say missing from supplier that we are waiting to receive in warehouse) – once issue is solved (inventory received in this case) warehouse guy enters the received quantity into grid view and the activity for this issue is basically solved. BTW there is not user login or user account logic implemented, there are two buttons on the main screen – 1 is used by manager to enter new or edit the case, -2 is a grid view used by warehouse guy. What I require is to add email logic and user logic to the process so if there is a change in a case or if there is a new case opened the related party receives email notification.