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. 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 the Real Estate Agency in a variety of different styles and colours.

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