What Mailbox Materials Are Allowed? (4 Materials Checked)

When buying a curbside mailbox, you want to give some thought to the material.

Not all materials are allowed. There are certain guidelines that manufacturers have to follow when making mailboxes.

If the mailbox is made of material that is considered inappropriate, it will be rejected.

Here are the mailbox materials that are allowed:

1. Plastic

A lot of curbside mailboxes are made of plastic.

It is inexpensive, but it protects your mail from moisture and other outdoor elements.

The most common type of plastic used for mailboxes is polypropylene because it is one of the most durable types of plastic.

One of the cons to plastic curbside mailboxes is that they are weak compared to those made of other materials.

Plastic can deform easily when exposed to surface pressure. Plastic also tends to fade and become brittle under direct exposure to sunlight.

Plastic mailboxes are best for locations where it does not get too hot.

2. Wood

Some curbside mailboxes are made of wood; however, it is not as commonly used as plastic curbside mailboxes.

Wooden mailboxes are sturdy, and they can add a warm and rustic look to your house.

The downside to wooden curbside mailboxes is that they are prone to rotting and decay. Wood is sturdy and durable, but it can decay easily when exposed to moisture and other outdoor elements.

It is also prone to mold and mildew growth. It would be best to treat your wooden curbside mailboxes with a protector spray.

When buying a wooden curbside mailbox, take note that only the box can be made of wood. The door and the mailbox flag should be made of plastic.

3. Ferrous Metal

Ferrous metal is another material that the USPS allows for curbside mailboxes. Ferrous metals refer to metals that have iron as their main component.

Curbside mailboxes made of ferrous metals are known to be very strong and durable. However, they are quite prone to rust when exposed to moisture, and the rust can spread fast.

You have to apply a protective coating if you choose to have a curbside mailbox made of ferrous metal. The protective coating will help prevent your mailbox from rusting.

Here are some examples of ferrous metals that mailboxes can be made out of:

  • Pure Iron
  • Steel
  • Carbon Steel

4. Non-Ferrous Metal

Curbside mailboxes can also be made of non-ferrous metal. Non-ferrous metal refers to metal that has very little to no iron content.

Curbside mailboxes made from non-ferrous metals are equally as durable as ferrous metals. The advantage of having these mailboxes is that they do not rust.

They can still corrode, but they do not rust. For corrosion, you can prevent it by applying a protective coating to your mailbox.

Here are some examples of non-ferrous metals that are used for mailboxes:

  • Aluminum
  • Titanium
  • Brass
  • Copper
  • Zinc

Can You Have a Custom-Made Mailbox?

When shopping for mailboxes, you might notice how the options can be limited. Some people repaint their mailboxes to match their house or if the color that they want is not available.

The good news is that if you want a very specific look or theme for your house, you can have a custom-made mailbox.

Custom-made mailboxes can be expensive. They can cost anywhere from $20 to $500, depending on the materials you will use.

It is cheaper if you do it yourself, but you can pay for a professional to construct your mailbox if you are not that handy.

One of the pros to having a custom-made mailbox is that there are many design possibilities. You can get creative with the flag and have a unique shape.

You can also have it painted in different colors.

A custom-made mailbox should meet the size and construction standards set by the USPS. Only then will it have the seal of approval from the Postmaster General (PMG).

Before having your custom mailbox constructed, you need to go to your local post office first and show the PMB your plans to have it approved.

What Materials Are Not Allowed?

Not all materials are allowed for making mailboxes.

Just because a certain material can hold mail does not mean that it will be allowed or approved by the USPS.

According to the USPS engineering standards and specifications, any toxic, flammable, or transparent material is not allowed.

It also says that materials with mechanical and chemical properties that do not meet the standards are not allowed.

So if you have a plastic mailbox that is transparent, it will not be allowed even if plastic is generally allowed. People should not be able to see the contents of your mailbox.

Any permanently fixed materials will also not be allowed. This means that you should easily be able to uninstall your mailbox when needed.

Any material that prevents that is not allowed.

Can a Mailbox Be Made of CONCRETE?

A mailbox cannot be made of concrete.

Technically, you can construct a concrete mailbox, but the USPS will not approve it.

To be able to build a concrete mailbox, you would still need to request a building permit, but it will never be approved.

One reason is that a concrete mailbox would be considered a “deadly fixed object.” When a vehicle accidentally hits it, it can cause serious damage.

The passengers can be fatally injured, and you could be sued. These rules protect homeowners from issues like these.

Can a Mailbox Be Made of BRICK?

A mailbox cannot be made of brick.

Brick mailboxes are also not allowed, and this is for the same reason that concrete mailboxes are not allowed.

Brick mailboxes would also be considered a “deadly fixed object,” so it is not an approved material for mailboxes.

Can a Mailbox Be Made of STONE?

A mailbox also cannot be made of stone.

This is for the same reason that concrete and brick mailboxes are not allowed. Permits will be required to build such mailboxes, and they never get approved.

Contractors would not build these for you if no building permits were given.

If you find a contractor who would build a mailbox made of concrete, brick, or stone without permits, you could lose a lot of money and possibly have a liability lawsuit.

For example, if you have paid a deposit to the contractor and he begins the construction, and a random inspection happens, you would be asked to stop the construction.

You would also be asked to remove any work that has been started, and you would not be able to get your money back from the deposit.

If the mailbox has already been built and a random inspection happens, you would be asked to dismantle the mailbox. That is just money for materials and labor down the drain.

Furthermore, if someone accidentally hits their car into your concrete, brick, or stone mailbox and the car gets damaged, and they get seriously injured, you can be sued.

Can a Mailbox Be Made of PLASTIC?

A mailbox can be made of plastic.

Plastic is one of the most common materials used for mailboxes. Plastic mailboxes are more affordable compared to mailboxes made from other materials.

Plus, they are light and durable, and they can protect your mail from any outdoor elements.

Can a Mailbox Be Made of WOOD?

A mailbox can be made of wood.

While wood is not commonly used for mailboxes, wooden mailboxes are allowed. They look nice, and they add a certain charm to your curbside.

When buying a wooden mailbox, remember that only the box can be made of wood. The handle and the flag should be made of plastic.

Can a Mailbox Be Made of STEEL?

A mailbox can be made of steel.

Steel is another popular material used for mailboxes. Steel is sturdy and durable. It is a versatile material that you can paint on if you want a specific color or are looking for your mailbox.

The only downside of having a steel mailbox is that it corrodes and rusts easily.

If you prefer to have a steel mailbox, make sure to apply powder coating to it to prevent rusting.

While mailboxes may not be the most exciting part of your house, you must choose the materials carefully. Check which materials work best for the climate in your area.

If you are planning to have a custom-made mailbox, make sure to check the specifications set by the USPS so that it will be approved.


What Materials Can Curbside Mailboxes Be Made Of?

Curbside Mailboxes: Mailbox Size & Construction Standards

U.S. Postal Service Standard For Mailboxes

So You Think You Want A Brick Mailbox