What happens when you tape 39 cents in postage to an envelope?...

[Jennie Hinchcliff]

The answer is here: http://www.monkeyfaq.com/mail/index.html

(I won't spoil the answer for you, but it's worth taking a look...)
Another interesting way to "work" the postal system.
--JH

[Jennie Hinchcliff]

Haven't seen anything in my mailbox yet, but will keep a look-out! And guess what?! Still haven't received the card which I mailed to myself. Hmm...both of your cards traveled all the way around the world, but mine can't even make it across town... :-)

[Ruud Janssen]

The text on my card: "Sorry, had no postage stamps" and my signature. The postal workers inside Breda will know it is from me and surely will play allong....

[Carla Cryptic]

That's one thing that's fun - the postal workers get to know us, don't they? Most of them find it interesting to see what we do and what we send/receive. I have enjoyed that a lot.

[Ruud Janssen]

This kind of mail might take its time. Lets wait a few more weeks before we say it failed....

[Kerry Jeffrey]

It's a very cool idea, but in the US almost all mail processing is automated. Anything that looks like an envelope goes through a series of machines that process 30,000 pieces of mail an hour where the envelopes pass through a series of belts and pinch points that can eject rigid articles (like coins). The trick would be to deposit the art piece with packages or other non-machinable items so that it doesn't go into the void. It sounds like some pieces went through. Good job!

[Ruud Janssen]

Some Postal Workers still value the handwork. They just help these kind of mail through the system. Just like it should be. If transport of communication is run by machines all becomes standard....

[andytgeezer]

Hahaha! What a great idea and a hilarious outcome! Nice one!

[Lois Richter]

I've been told that USPS sorting machines can get broken if non-bendable items are sent thru them.  So the post office has created separate handling for thick or non-bendable items (with a slightly higher fee).  I'm familiar with this problem because of hosting ATC swaps where some of the ATCs were stiff and needed to be handled separately.  Since my goal was to get everything back to the players intact, I just followed USPS recommended procedures and never had a problem.  (Several of the players, however, lost some or all of their ATCs by sending stiff cards to me without separate handling.  The envelopes ripped in processing and cards fell out.) 

My guess is that the smaller a post office is, the likelier it is a human would notice taped-on coins before they got to a sorting machine.