Mailbox

In every game, a red Mailbox can be found outside the player's house. It is where Pete puts Letters addressed to the player. When a letter arrives, a blue signal with a small blinking letter will appear on the right-top of the mailbox and will make a faint beeping sound when the player walks near it. In, a full mailbox will be indicated by faster beeping and the mailbox will shake rapidly. Only the owner of the house can open the mailbox of their home.

In
In, different forms of mailboxes are available to buy from Tom Nook at his new shop, Nook's Homes, in a variety of different styles and colors. New mailboxes cost 3,600 bells. There are 21 different styles to choose from. Each style has a theme, such as Fairy Tale, Antique, or Trendy. When a player's mailbox is full, it will shake violently, beep very loudly, and the flap will snap open and shut. It will shake faster and faster the closer a player walks to it. If a player has a full mail box, Pete the mail pelican will try to tell the other players about it. As the villager exits their house, Pete will greet him or her and ask them to tell their friend to clear their mailbox since it is full. After giving the player the message, Pete will wander around for awhile and let the player speak to him.

House showing a customized mailbox in the mermaid style.

Appearances in other games
In Super Smash Bros. Brawl, one of the trophies available features a male player, and next to him is a mailbox which holds unread mail, shown by the blue sign on the mailbox.