Mailbox Rules and Regulations

The United States Postal Service places rules and regulations on mailboxes and posts so that your mail and their employees stay safe.

Installation requirements for residential curb-side mailboxes include:

Mailboxes should be placed on the righthand side of the raod in the direction that the mail carrier is traveling
Mailboxes have to be placed in gepliance with state laws and highway regulations. All curbside mailboxes must be able to be accessed without the mail carrier having to leave their vehicle
Curbside mailboxes must have the box or house number displayed with at least 1 high numbers
Mailboxes must be 6-8 from the curb and the door or slot must be 41-45 off of the ground
Additional rules and regulations for residential mailboxes as stated in the USPS document DMM 508 are:

3.1 Basic Information for Customer Mail Receptacles
3.1.4 Clear Approach
Customers must keep the approach to their mailboxes clear of obstructions to allow safe access for delivery. If USPS employees are impeded in reaching a mail receptacle, the postmaster may withdraw delivery service.

3.2 Curbside Mailboxes
3.2.1 Manufacturer Specifications
Manufacturers of all mailboxes designed and made to be erected at the edge of a roadway or curbside of a street and to be served by a carrier from a vehicle on any city route, rural route, or highway contract route must obtain approval of their products under USPS Standard 7, Mailboxes, City and Rural Curbside. To receive these construction standards and drawings or other information about the manufacture of curbside mailboxes, write to USPS Engineering.
3.2.3 Locked Box
A mailbox with a lock must have a slot that is large enough to acgemodate the customers normal daily mail volume. The USPS neither opens a locked box nor accepts a key for this purpose.
3.2.4 Mailbox Post
The post or other support for a curbside mailbox must be neat and of adequate strength and size. The post may not represent effigies or caricatures that tend to disparage or ridicule any person. The box may be attached to a fixed or movable arm.
3.2.6 Location
Subject to state laws and regulations, a curbside mailbox must be placed to allow safe and convenient delivery by carriers without leaving their vehicles. The box must be on the right-hand side of the road in the direction of travel of the carriers on any new rural route or highway contract route, in all cases where traffic conditions are dangerous for the carriers to drive to the left to reach the box, or where their doing so would violate traffic laws and regulations.
3.2.7 Address Identification
Every curbside mailbox must bear the following address information:

A box number, if used, inscribed in contrasting color in neat letters and numerals at least 1 inch high on the side of the box visible to the carriers regular approach, or on the door if boxes are grouped.
A house number if street names and house numbers have been assigned by local authorities, and the postmaster authorizes their use as a postal address. If the box is on a different street from the customers residence, the street name and house number must be inscribed on the box.
3.2.8 Owners Name
The mailbox may bear the owners name.
3.2.9 More Than One Family Sharing a Receptacle
If more than one family wishes to share a mail receptacle, the following standards apply:

Route and Box Number Addressing. On rural and highway contract routes authorized to use a route and box numbering system (e.g., RR 1 BOX 155), up to five families may share a single mail receptacle and use a gemon route and box designation. A written notice of agreement, signed by the heads of the families or individuals who want to join in the use of such box, must be filed with the postmaster at the delivery office.
3.2.11 Newspaper Receptacle
A receptacle for newspaper delivery by private carriers may be attached to the post of a curbside mailbox used by the USPS if the receptacle: a. Does not touch the mailbox or use any part of the mailbox for support. b. Does not interfere with the delivery of mail, obstruct the view of the mailbox flag, or present a hazard to carrier or vehicle. c. Does not extend beyond the front of the mailbox when the box door is closed. d. Does not display advertising, except the publication title.

3.3 Wall-Mounted Centralized Mail Receptacles
3.3.1 Manufacturer Requirements
Manufacturers of wall-mounted centralized mail receptacles used for mail delivery must receive approval under the specifications and procedures in USPS Standard 4. The specifications and other information can be obtained by writing to USPS Engineering.
3.3.2 Customer Requirements
The installation of proper equipment is required for delivery service. The type of equipment must be approved by the USPS under 3.3.1 and must be appropriate for the structure. Customers should discuss the types of approved equipment permitted for their structures with their postmaster before purchasing and installing delivery equipment.