Postal Specialties
Postal Specialties
ALUMINUM · STAINLESS · BRASS

Commercial Mailbox Solutions

Individual horizontal, vertical, and wall-mount commercial mailbox solutions for office buildings, apartments, and commercial lobbies. From USPS-approved rear-loading mailboxes to decorative brass lobby units. Surface-mounted installation by RPS Building Specialties across Southern California.

Commercial Mailbox Types

From USPS-approved horizontal rear-loading units to decorative brass lobby mailboxes, we supply the full range of commercial mailbox solutions for any building application.

Horizontal Mailboxes (Rear-Loading)

Recessed in wall, carrier accesses from rear service corridor. Tenant accesses from front with key. Aluminum construction, USPS-approved. 5-door through 10-door+ configurations.

Florence Salsbury

Vertical Mailboxes (Front-Loading)

Surface-mounted or recessed. Both carrier and tenant access from front. Column-style stacked compartments. Compact footprint for narrow lobbies. 5-tenant through 16-tenant configurations.

Florence Salsbury

Outdoor Collection Boxes

Freestanding or wall-mounted letter collection. Secure outgoing mail with anti-fishing design. Weather-resistant aluminum/powder-coated steel. After-hours document drop boxes.

COMMODITY

Interoffice Mail Systems

Internal mail distribution for corporate offices. Departmental sorting stations. Non-USPS internal routing. Wall-mounted or freestanding.

COMMODITY

Decorative Brass Mailboxes

Premium lobbies, luxury residential/commercial. Polished, brushed, lacquered, or patina finishes. Traditional aesthetic for upscale environments.

PREMIUM
48"

ADA-Compliant Configurations

Operable parts max 48" above floor. Clear floor space for wheelchair approach. Forward and side approach mounting heights. Accessible route compliance.

ADA REQUIRED

Mailbox Materials & Finishes

Choosing the right material determines your mailbox's durability, appearance, and maintenance requirements — especially in Southern California's diverse climate zones.

Standard Materials

  • Aluminum — Most common, USPS standard, lightweight, corrosion-resistant, and the most cost-effective option for commercial mailboxes
  • Stainless steel — Premium, vandal-resistant, ideal for high-traffic lobbies, modern appearance, Type 304 or 316 for coastal
  • Brass — Decorative, premium lobbies, traditional aesthetic, available in polished, brushed, lacquered, or patina finishes
  • Powder-coated steel — Outdoor collection boxes, drop boxes, weather-resistant with custom color options

SoCal Recommendations

  • Coastal locations — Aluminum (standard, corrosion-resistant) or stainless steel (Type 316) for high-traffic coastal lobbies
  • Inland locations — Aluminum offers the best value and is the USPS standard for all commercial mailbox installations
  • Premium lobbies — Brass or stainless steel for luxury apartments, upscale offices, and high-end commercial buildings
  • Outdoor drop boxes — Powder-coated steel for weather resistance, UV protection, and vandal deterrence

ADA Compliance Standards

Commercial mailbox installations must meet ADA accessibility requirements. RPS verifies compliant mounting heights on every project.

ADA Mailbox Mounting Requirements

Height Requirements

  • Operable parts (locks, doors) max 48" above finished floor
  • Forward approach: max 48" reach, min 15" above floor
  • Side approach: max 54" reach, min 15" above floor

Access Requirements

  • Clear floor space: minimum 30" x 48" for wheelchair approach
  • Accessible route to mailbox location required
  • Easy-to-operate locks and handles (no tight grasping or twisting)
  • Visual contrast between mailbox doors and surrounding wall

Installation Strengths & Considerations

An honest look at RPS commercial mailbox installation capabilities and what falls outside our scope.

Strengths

  • Surface-mounted to existing walls (vertical mailboxes)
  • Recessed installation into pre-cut wall openings (horizontal)
  • Pedestal-mounted freestanding units
  • ADA mounting height verification
  • USPS-approved product selection
  • Multiple finish and material options

Considerations

  • Wall opening cutting for recessed units referred to GC
  • In-ground foundations referred to concrete contractor
  • USPS arrow lock provided by USPS (not RPS)
  • Brass mailboxes require periodic polishing maintenance

Choosing Commercial Mailboxes for Your Building

Commercial mailboxes are a required building component for any multi-tenant office, apartment complex, condominium, or mixed-use building that receives USPS mail delivery. Selecting the right mailbox type, material, and configuration depends on your building's layout, lobby space, the number of tenants, and whether a rear service corridor is available for carrier access. In Southern California, where building types range from modern high-rise lobbies to mid-century garden-style apartments, RPS Building Specialties provides the full spectrum of commercial mailbox solutions to fit any architectural context.

Horizontal vs. Vertical Mailboxes

The two primary commercial mailbox configurations are horizontal (rear-loading) and vertical (front-loading). Horizontal rear-loading mailboxes are the traditional standard for apartment buildings and office complexes where a service corridor or utility room exists behind the mailbox wall. The USPS carrier accesses the mailboxes from the rear corridor, while tenants access their individual compartments from the front lobby side using a key. These units are recessed into the wall during construction or renovation.

Vertical front-loading mailboxes are surface-mounted or recessed into the lobby wall, with both the carrier and tenant accessing from the same front side. Vertical units use a column-style layout with stacked compartments, making them ideal for narrow lobbies, hallways, and retrofit installations where a rear service corridor does not exist. Their compact footprint makes them the preferred choice when lobby space is limited.

ADA Requirements for Commercial Mailboxes

The Americans with Disabilities Act establishes specific requirements for commercial mailbox installations. All operable parts — including locks, doors, and handles — must be mounted no higher than 48 inches above the finished floor for forward wheelchair approach and no higher than 54 inches for side approach. The minimum mounting height is 15 inches above the floor. A clear floor space of at least 30 by 48 inches must be maintained in front of the mailbox for wheelchair approach, and the accessible route to the mailbox location must be at least 36 inches wide. RPS Building Specialties verifies ADA-compliant mounting heights during every commercial mailbox installation.

Materials for the Southern California Climate

Aluminum is the USPS standard material for commercial mailboxes and performs exceptionally well in Southern California's climate. It is lightweight, naturally corrosion-resistant, and offers the best value for most installations. For coastal locations, aluminum remains the standard choice, though stainless steel (Type 316) provides superior vandal resistance and a premium appearance for high-traffic lobbies. Brass mailboxes deliver a decorative, traditional aesthetic that is ideal for luxury apartment lobbies and high-end office buildings, available in polished, brushed, lacquered, or aged patina finishes. Outdoor collection boxes and document drop boxes are typically constructed from powder-coated steel for maximum weather resistance and UV protection.

USPS Regulations for Private Delivery Mailboxes

Only USPS-approved mailboxes may receive mail delivered by USPS carriers. These mailboxes must include the USPS arrow lock for carrier access and meet USPS standards for compartment size, security, and construction. The USPS arrow lock is provided by the local post office — not by the mailbox manufacturer or installer. Private delivery mailboxes (for interoffice mail, courier services, or internal document distribution) do not require USPS approval and can be configured more flexibly. If your tenants receive USPS mail, you must use USPS-approved mailbox units.

Related Postal Products

In addition to individual commercial mailboxes, RPS Building Specialties supplies and installs cluster mailboxes (CBU units) for outdoor multi-tenant mail delivery, and parcel lockers for secure package delivery in apartment and office complexes. Visit our Postal Specialties hub page for our complete catalog of mail and package delivery solutions.

Contact us at (714) 381-4196 or [email protected] for a free consultation and project quote on commercial mailbox supply and installation anywhere in Southern California.

Other Postal Products

Frequently Asked Questions

Common questions about commercial mailbox types, materials, ADA requirements, and installation answered by our product specialists.

Horizontal rear-loading mailboxes are recessed into a wall with the USPS carrier accessing from the rear (through a service corridor or utility room) and tenants accessing from the front with a key. This is the traditional configuration for apartment buildings and office buildings where a service corridor exists behind the mailbox wall. Vertical front-loading mailboxes are surface-mounted or recessed into a wall with both the carrier and tenant accessing from the front. Vertical units have a column-style layout with stacked compartments, making them ideal for narrow lobbies and hallways where space is limited. RPS installs both types — surface-mounted vertical units bolted to existing walls, and recessed horizontal units installed into pre-cut wall openings.

The Americans with Disabilities Act requires that mailbox operable parts (locks, doors, handles) be no higher than 48 inches above the finished floor for forward approach and 54 inches for side approach. The minimum height is 15 inches above the floor. A clear floor space of at least 30 by 48 inches must be maintained in front of the mailbox for wheelchair approach. The accessible route to the mailbox location must be at least 36 inches wide with no obstructions. Locks and handles must be operable with one hand without tight grasping, pinching, or wrist twisting. RPS Building Specialties verifies ADA-compliant mounting heights during every installation.

The four primary materials are aluminum, stainless steel, brass, and powder-coated steel. Aluminum is the most common and is the USPS standard for commercial mailboxes — it is lightweight, corrosion-resistant, and the most cost-effective option. Stainless steel (Type 304 or 316 for coastal locations) offers premium durability, vandal resistance, and a modern appearance for high-traffic lobbies. Brass provides a decorative, traditional aesthetic ideal for luxury apartment lobbies, historic buildings, and high-end office lobbies — available in polished, brushed, lacquered, or patina finishes. Powder-coated steel is used primarily for outdoor collection boxes and drop boxes where weather resistance is essential.

Yes. RPS installs horizontal rear-loading mailbox units into existing pre-cut wall openings. The wall opening must already be cut to the manufacturer's specified dimensions before our installation. If the opening needs to be created, RPS coordinates with a general contractor to cut the opening to the correct size. Once the opening is prepared, RPS sets the mailbox unit into the opening and secures it with screws through the mounting flange. We verify level, plumb, and proper alignment of all compartment doors. For vertical front-loading mailboxes, RPS surface-mounts the unit directly to the existing wall using lag bolts into wall studs or expansion anchors into concrete block.

USPS-approved mailboxes are manufactured to USPS specifications and approved for use in the federal mail delivery system. Only USPS-approved mailboxes may receive mail delivered by USPS carriers. These mailboxes include the USPS arrow lock for carrier access and meet USPS standards for size, security, and construction. Private delivery mailboxes are designed for non-USPS delivery services such as interoffice mail, courier services, or private document distribution. Private mailboxes do not need USPS approval and can be configured more flexibly for specific organizational needs. If your tenants or offices receive USPS mail, you must use USPS-approved mailbox units. RPS supplies and installs both USPS-approved and private delivery mailbox systems.

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