Surface Mount

What Are Surface Mount Mailboxes?

A surface mount mailbox is a multi-tenant mail unit that installs directly onto a finished wall using a surface mount collar or enclosure, with no rough-cut wall opening required. Unlike a recessed unit, the mailbox projects from the wall instead of sitting flush inside it. This page covers our full catalog of Florence and Salsbury surface-mounted units: USPS-STD-4C horizontal mailboxes and 4B+ vertical mailboxes, in configurations from 2 to 29+ compartments, built for apartments, condos, and commercial buildings. The guide below helps you confirm which type fits your project before you click into a product.

Surface Mount vs Recessed Mailbox: When to Choose Each

A surface mount mailbox installs over the finished wall using a surface mount collar, while a recessed mailbox sits inside a framed wall opening. Choose surface mount when:

• Wall depth is too shallow for a recessed unit
• The wall finish is complete and cannot be cut into
• You are retrofitting or replacing mailboxes in an occupied building
• The project timeline does not allow framing rework
• You want a faster, lower-cost installation

Choose recessed for new construction with full wall depth and when a flush, built-in look is the priority. Recessed installation adds framing labor cost but disappears into the wall. If that fits your project, browse our recessed 4C horizontal mailboxes instead.

4C Horizontal Surface Mount Mailboxes (USPS-Approved for New Construction)

Every 4C surface mount mailbox we carry meets USPS-STD-4C, the standard the USPS Builders & Developers Guide requires for new construction and major renovations. Like all our 4C horizontal mailboxes, these units are front-loading only. USPS sets the parcel-locker requirement across the full installation, not per unit, so many 4C configurations include integrated lockers while door-only units can be paired with dedicated parcel-locker units to meet the ratio.

Each unit pairs with a surface mount collar in heavy-gauge aluminum, powder coated to match the mailbox finish, with hidden fasteners for a clean installed appearance. Configurations run from 2 to 29+ tenant doors, ADA-compliant variants keep all compartments within accessible reach range, and with a weatherproof powder coat finish these 4C units are rated for indoor or outdoor installation.

4B+ Vertical Surface Mount Mailboxes (Replacement-Only)

Our surface mount vertical mailboxes catalog covers the Florence 1250 series and Salsbury 3500 series. Both meet USPS-STD-4B+, which USPS-STD-4C superseded for new construction and major renovations in 2006, so they are approved for replacement and retrofit installations only. They cannot be specified for new construction, but they remain the straightforward choice for like-for-like replacement during renovations.

These vertical mailboxes are designed for indoor or weather-protected locations only. Each unit holds 3 to 7 tenant compartments and secures with a 5-pin cylinder cam lock. Both series are top-loading: the compartment array tilts forward so mail drops in from the top. Salsbury 3500 doors measure 5-1/2″ W x 16-1/4″ H x 6-3/4″ D; Florence 1250 units differ slightly, with exact sizes on each product page. The surface mount collar option lets you install on walls where depth or finish rules out recessing.

Surface Mount Mailbox Sizes and Configurations

Match tenant count and wall space to a unit type before you open a product page. Every 4C surface mount mailbox spans 2 to 29+ tenant doors in single or double column layouts, built up to 16 doors high, and ADA-compliant variants cap unit height so every compartment stays within the reach ranges defined in the ADA Standards for Accessible Design. Many 4C configurations include integrated parcel lockers in a range of sizes; door-only units are also available, listed on each product page.

Each 4B+ vertical mailbox holds 3 to 7 compartments and stacks up to 2 units high, with tenant compartments measuring 5-1/2″ W x 16-1/4″ H x 6-3/4″ D. Overall unit dimensions vary by configuration and are listed on each product page. The collar or enclosure adds wall projection of roughly the mailbox depth, so confirm clearance in corridors and entryways when comparing surface mount mailbox configurations.

Surface Mount Mailbox Features

Every unit in this category is built for daily multi-tenant use. The feature set that drives the purchase decision:

• Construction and materials: Heavy-gauge aluminum bodies with 300 series stainless steel components on 4C units. 4C horizontal units come in a powder coat finish, with eight architectural colors from Florence (antique bronze, black, dark bronze, gold speck, postal grey, sandstone, silver speck, white) and four from Salsbury (aluminum, bronze, gold, sandstone). For vertical units, Florence 1250 comes in a grooved anodized aluminum finish and Salsbury 3500 in a powder coat finish (aluminum, brass, bronze, green, sandstone).
• Security: 5-pin cylinder cam locks on tenant doors, with three keys per tenant lock on 4C units. Master doors accept USPS arrow locks or private master locks, and 4C parcel lockers are double-locking. Compare locking mailbox options across our catalog.
• Loading and access: 4C units are front-loading with an outgoing mail slot included; 4B+ vertical units are top-loading. Both are available in USPS access and private access variants.
• Installation and aesthetics: The surface mount collar (Florence) or enclosure (Salsbury) is built from heavy-gauge aluminum with a matching powder coat finish and hidden fasteners. Mounting hardware depends on the product: Florence 4C collars include it, while Salsbury vertical units do not, so check the product page.

Florence commercial mailboxes carry a 5-year manufacturer warranty.

How Surface Mount Mailboxes Install

Surface mount mailbox installation stays simple: the surface mount collar or enclosure is the key install component, framing the unit and anchoring it to the wall. Whether mounting hardware is included depends on the manufacturer, so check the product page. Wood-stud walls are the standard anchor target; masonry and concrete work with appropriate anchors. For any USPS-serviced installation, consult your local Postmaster before ordering so the master lock and placement meet delivery requirements. Professional installation is available. Check the installation guide included with each product. If you need a freestanding option, a surface mount mailbox post bolts directly to a concrete pad.

Why Choose Our Surface Mount Mailboxes

MailboxWorks stocks both Florence and Salsbury, 4C horizontal and vertical, all on one page. While Florence’s own site sends buyers out to dealers and most competitors stock a single brand, we ship both from one catalog. As an established commercial mailbox supplier, we offer bulk pricing on commercial quantities and multi-building orders, and our expert support line answers USPS compliance questions before you commit to a spec. Orders over $30 ship free.

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