Here are all mailboxes guide in Yoku’s Island Express game. hope this simple guide will help you. if you want to get all achievement. just click this guide.
This guide allows you to find all the mailboxes in the game. Getting the first 10 mailboxes will unlock the overdue packages sidequest. While getting them all will award you a wickerling.
The mailboxes are numbered in the image so it’s easier to find them in the video.
The video on youtube has the timestamps for the mailboxes as numbered in the image.