Now...only if you could get the post man to set it at the front door and light it on fire...knock ...then run
I am not advocating that anyone do this, as it would more likely then not be illegal on a Federal level. If you send a package via USPS and the package is too large for a mailbox, the mailman will usually put the package on your front doorstep (it will probably be pretty rare that they will knock on the door though). You could put a GPS device that automatically ignites a lighter once the package gets to the delivery address and stays there for a certain amount of time.
Alternatively, when UPS and/or FedEx deliver a package to a residence and a signature is not required, they will almost always, put the package on your front door, ring the doorbell/knock on the door and immediately leave....