I bought this 'puzzle post-card' in Amalfi, Itlay.
You can write on them and send them in the mail. This one however, when I got back to our room and opened it, is just a puzzle you write on the back and send in an envelope. There is no way to send it as a postcard even though you can see the title.... 'puzzle post-card'.
This unused postcard was bought in 2009.