Every business needs to be able to receive mail, be it bills, licenses or packages. In order to receive mail, you must adhere to the United States Postal Service rules and regulations for mail delivery. The rules vary based on how and where you intend to receive your mail.

Individual Boxes vs. Cluster Mailboxes

USPS residential mailbox regulations largely focus on whether you have a cluster mailbox or an individual mailbox. Cluster mailboxes are units that contain multiple boxes for multiple addresses all in one unit, while individual mailboxes may be next to one another on one post, but each one is its own unit.

The post office prefers cluster mailboxes because they speed up the delivery process, and recent regulations require new individual mailboxes to be grouped two to a property line where possible in order to expedite deliveries. Developers building new communities are often surprised to learn that the post office will only allow them to set up delivery to cluster mailboxes even if each property in the community spans multiple acres. Local postmasters can issue exceptions to these rules as needed.

Individual Mailbox Regulations

You can't just grab any old box, stick it on the sidewalk and hope to actually get mail delivered to it. If you're buying a premade mailbox, always get one that has the postmaster general's seal of approval. If you choose to make your own, it will need to meet the same standards as commercial mailboxes, so take your plans to the local postmaster before building it in order to get approval.

Approved boxes can be approximately 18.56 to 23.81 inches long, 6.25 to 11 inches wide and 6 to 15 inches tall. The post office recently approved a new commercially available size of box that better accommodates packages. It is 13.63 inches wide, 7.75 inches tall on the side, 12 inches tall at the center and 16.5 inches deep.

Whatever size mailbox you choose, put your house or apartment number on the box, and if it is located on a different street than your home or apartment, put your full street address on it.

Individual Mailbox Height and Placement

If you have a mailbox, you need to install it properly in order to receive mail. The mailbox height should be between 41 and 45 inches from the road surface (not sidewalk) to the bottom of the mailbox or point of mail entry. The box should be placed 6 to 8 inches back from the curb so the delivery person can drop off mail without getting out of his vehicle. Boxes that must be attached to the house should be easily accessed from the sidewalk, steps or porch.

The USPS knows that cars sometimes hit mail boxes, so for safety's sake, they recommend that all posts are stable but still able to fall over or bend if hit. For that reason, they suggest using a 4-inch by 4-inch wooden support or a 2-inch diameter aluminum or steel pipe. Unyielding supports like heavy metal pipes and concrete posts should be avoided. They also advise that the post be buried no more than 24 inch deep. These post suggestions are not mandatory but are advised to help keep them from being dangerous to drivers who might hit them in an accident.

Cluster Mailbox Rules

Like individual mailboxes, commercially available USPS cluster mailbox regulations state that the boxes must be approved by the postmaster general before they are put up for sale. The units may be sold with a wide variety of door numbers and may come in a variety of shapes, with some being rather narrow and others being mostly square shaped. Most units also have a few larger doors for package delivery. Developers may also choose to install one or more additional boxes that only have package-sized compartments. The numbers on the boxes may or may not be associated with the addressee's street address. Developers may choose to install these units indoors or outdoors, with indoor units being more common for places like indoor apartment complexes. Outdoor units may be decorated with lights, shade or other enhancements to enable the boxes to better fit in with neighborhood aesthetics.

If the post office owns these units, they will distribute three keys to each property owner, who must return the keys at the time that he vacates the property. If the boxes are owned by a private entity, that person or company must distribute the keys as seen fit.

Door Slot Rules

The USPS will no longer deliver mail to the door of new addresses. Addresses with existing door slots must ensure they meet USPS requirements and have openings between 1.5 and 7 inches tall and be at least 30 inches above the floor. Horizontal slots must have a flap hinged at the top, and vertical slots must be hinged on the opposite side of the door's hinges.

Nondeliverable Addresses

There are some areas where the USPS will not deliver to individual addresses at all, and the residents must pick up their mail at the local post office. This could be due to local ordinances, weather or safety concerns. Generally, those required to pick up their mail will not be required to pay for their post office box.

At addresses that are deliverable, the carrier must be able to get to your mailbox safely. If a delivery person cannot get to your mailbox safely, she can bring the mail back to the post office. Safety hazards may include unsafe stairways, loose dogs, icy conditions and more. If the hazard is not taken care of, the USPS may even require the customer to get a post office box.

USPS General Delivery

Individuals who cannot receive mail at a standard delivery address may elect to use general delivery instead. That means you can elect to pick up your mail at a post office in the city of your choice. To do this, you will need to have your mail addressed with your name, the words "general delivery" and the city, state and zip+4 code of the local post office. For example:

John Smith
General Delivery
City, State 12345-9999

General delivery will only be available at the main post office in a town or city with more than one post office location.

USPS Package Deliveries

Packages and other items may not be delivered to mailboxes by any entity but the USPS according to federal law. This is why companies such as FedEx and UPS will only deliver to home or business addresses through the front door. This is also why they will always leave delivery slips on the door rather than in the mailbox. These agencies cannot deliver to post office boxes or mail addressed with general delivery.

This is why some people and companies choose to get a mailbox at private companies such as Mail Boxes Etc. or FedEx locations. Since mail delivered to these businesses is addressed to a real location (123 Main St. #115, for example), any delivery service may deposit mail in these boxes. This is also useful for situations where a "real address" is required and a post office box will not be accepted, such as with credit card companies.

As for the USPS package delivery policy, the agency will deliver packages in mailboxes if space allows. Otherwise, the carrier may leave it on the home or business's porch or leave a delivery slip telling the customer to pick it up at the local post office.