Image Mailboxes about mail

In the United States, private companies such as FedEx and UPS compete with the federal government's United States Postal Service, particularly in package delivery. Different mailboxes are also provided for local and express service. (The USPS has a monopoly on First Class and Standard Mail delivery.)

File extension BAK refers to a backup data file
Learn more about files, files extensions and how top open file with unknown extensions at File Extension Database