In "Mountain Wedding" S-3/EP-31 Ernest T Bass "Writes" a note & wraps it around a rock, and heaves it through the "Darling's" Window while trying to court Charlene Darling. However 2 seasons later in S-5/EP-4 "The education of Ernest T Bass" we see that Ernest cannot read or write as he tries to learn so he can get a girl!
Think he had his mother figure come up in the hills helpin' him write the note?
Have you ever noticed that the "Mail Slot" wasn't in the door of the Courthouse in the early episodes.
There was one episode where Barney went to the post office to pick up the mail. There were at least two others that featured a mailman delivering the mail, and in one he he refused to hand the mail to Andy, telling him he wasn't a certified U.S. mail receptacle.