It is an essenti al thing in a sometimes crazy world. The more mail artists there are, the better the world will become because the lack of communication nowadays is sometimes very destructive. Some mail artists like to see mail art as art too. They judge it as other art, menti on famous people, make a difference between good and bad mail art. But this has nothing to do with mail art.
Mail art is a direct communication between individuals.
No galleries, no mu seums, no shop you can buy it in. Mail art is exchange only. So to get mail art you will have to send it out. Mostly the mail art that is transported all over the world ends up in some archive. If the archive is big enough the museums sometimes get interested because some mail artists actually participate in the conventional art-world too.