When I was a kid in the 70s, teachers would do pen pal exchanges with classes in other parts of the country or world. I got a couple pen pals that way but they never really lasted. When I was in the 5th or 6th grade, I was pen pals with my cousin in England. That was kind of fun and we wrote for a while.
These days there are all these privacy concerns and nobody uses the mail. Email does seem smarter.