David Aber has turned into a mailbox hunter extraordinaire (though he's told me that he doesn't go hunting; he just spots the mailboxes on his travels).
He calls this one Electrical Box. The pipes are electrical conduit and fittings, painted green. Let's take a closer look…
And the other side:
He emailed these photos to me on May 17th, which is also the date his camera's data says they were taken. Thanks for this unique find, Dave!