I wish we could send messages via birds like in the old days. Imagine sending messages across village. Yes it’s kinda useless, but it could also be fun.
i like the idea you can build a dovecote/birdhouse and name it. and when you put a letter in, you will see all the places listed you can send a letter to. then the bird will fly of screen.
maybe you can seal the letters with bee wax. so you can see which are unopened letters.