The designers have addressed half of the usage modes for a mailbox, and the less important one at that.
In addition to turning on a light, trigger a wifi signal that can be picked up inside the house. Sure, there are technical problems getting a radio pulse out of the metal box to wherever the wifi hub is, it may mean getting a whole 'nother mailbox with the functionality built in. (and the certification nightmare that entails)
But a mailbox that can tell you when the mailbox has new mail for you, ready to be retrieved, that would be a gadget worth getting!
