My parents' handwriting was borderline illegible, so they took to typing letters on a manual typewriter. Typewriters suffering from all the problems of complex finicky mechanisms, and being a write-only medium, resulted in a pleasing quirkiness that is completely absent from email. Read enough typed text, and you begin to recognize a person's particular "hand" at the typewriter, as well as the machine's individual quirks. Electric typewriters put an end to most of that, and email finished it off.