Mail boxes are a type of receptacle used for the storage and delivery of mail. They can be found in many places, such as post offices, businesses, and residential homes. Packages (8 letters) are items that are sent through the mail, such as parcels, letters, and other items. Etc (3 letters) is an abbreviation for 'etcetera, ' which is a Latin phrase meaning 'and other things.' Mail boxes are used to store and deliver packages, letters, and other items, etc.