The artist, Jenifer Wightman, writes:

In my several trips to the Kensington Post Office, I got to know one of the workers, who threatened to eat, rather than deliver these valentines. As a bribe, I said I would bring cookies. So, RETURN TO SENDER was hand-delivered to the Kensington Post Office.

This has been a very fun, satisfying, and humanizing project. Thanks all for playing.