Funny enough, my grandmother told me about a version of this scam, but as a prank. Get some roadkill, put it in a sealed bag. Put that bag in a box. Mail it the slowest way possible to a far away address that doesn't exist. Put your target's address for the Return Address. Be sure to do it in summer. By the time it gets to them... yuck.

Nana, you were weird. But still miss you.