Mail art is a way that artists can share work with other like-minded practitioners all over the world - it is a wonderful way to connect with others, and share your work.  
Here are some of my submissions to others' mail art calls, and lots of links.  
Send your link if you'd like to be added here:
emtheartist (at) yahoo.com.
(you'll have to type it - I am hiding from the spam makers)