Mailbox Size & Construction Standards
A mailbox with the Postmaster General's (PMG) seal of approval meets USPS size and construction standards. If you build your own mailbox or buy a custom-made one, it must meet the PMG standards. Show your local postmaster your mailbox plans or your custom-made box for approval.
Want to buy a mailbox big enough for packages? See Fortknox Mailboxes.
Where to Place the Mailbox
Here are some helpful guidelines to follow when placing your mailbox:
- Position your mailbox 41″ to 45″ from the road surface to the bottom of the mailbox or point of mail entry.
- Place your mailbox 6″ to 8″ back from the curb. If you do not have a raised curb, contact your local postmaster for guidance.
- Put your house or apartment number on the mailbox.
- If your mailbox is on a different street from your house or apartment, put your full street address on the box.
Installing the Mailbox Post
The best mailbox supports are stable but bend or fall away if a car hits them. The Federal Highway Administration recommends:
- A 4″ x 4″ wooden support or a 2″-diameter standard steel or aluminum pipe.
- Avoid unyielding and potentially dangerous supports, like heavy metal pipes, concrete posts, and farm equipment (e.g., milk cans filled with concrete).
- Bury your post no more than 24″ deep.
Fort Knox Mailbox Maintenance
Maintaining your Fort Knox mailbox is crucial for protecting your mail from unauthorized access, preventing damage caused by weather elements, and extending the lifespan of your mailbox. By following our step-by-step instructions, you'll be able to perform routine maintenance with ease, saving time and money on repairs down the line.