Best 6-Unit Cluster Mailboxes for Shared Mail Delivery
The closest matches for a six-unit mailbox are Salsbury Industries’ six-door vertical mailboxes, available in recessed and surface-mounted styles. The recessed models suit installations built into a wall, while the surface-mounted model is for mounting on a wall face. These are not the same as USPS-access cluster box units (CBUs); the listed CBU alternatives have four or eight customer doors instead of six. Compare the options below with your installation and postal-service needs in mind.
| Product | Best for | Configuration |
|---|---|---|
| Salsbury 3506ARP | Recessed mounting with master commercial lock | 6 doors |
| Salsbury 3506SRU | Recessed mounting with USPS-lock preparation | 6 doors |
| Salsbury 3506ASP | Surface mounting with master commercial lock | 6 doors |
| Salsbury 3308BLK-U | USPS-access service with eight customer compartments | 8 doors, 2 parcel lockers |
| Salsbury 3305BLK-U | USPS-access service with larger C-size compartments | 4 doors, 2 parcel lockers |
Salsbury 3506ARP Recessed Six-Door Mailbox
This aluminum, recessed-mounted model is best for a six-unit property that wants individual locked compartments and a master commercial lock. Each compartment measures 5-1/2 inches wide by 16-1/4 inches high by 6-3/4 inches deep. The individual doors have five-pin cylinder cam locks and come with two keys each; the master commercial lock also includes two keys.
Choose this model if the master-lock arrangement and recessed installation match your building plan. It was selected because it provides six private compartments in a single vertical mailbox. Its narrow compartment width may not suit every kind of mail or package, and the product is not identified as a USPS-access CBU.
Salsbury 3506SRU Recessed Six-Door Mailbox
The 3506SRU is best for a six-unit installation that requires a recessed mailbox and is intended to use a USPS lock. Salsbury lists it as manufactured to USPS-STD-4B+ specifications. Each compartment measures 5-1/2 inches wide by 16-1/4 inches high by 6-3/4 inches deep, and each door has a five-pin cylinder cam lock with two keys.
Choose this option when its stated USPS-lock use and recessed format fit the planned installation. The product information does not list a master commercial lock, so avoid assuming it offers the same master-key arrangement as the 3506ARP. Confirm lock and installation requirements with the relevant postal authority before ordering.
Salsbury 3506ASP Surface-Mounted Mailbox
This six-door aluminum mailbox is best for a shared property where the mailbox will be surface-mounted rather than recessed. It includes a master commercial lock with two keys. Each of its individual compartments measures 5-1/2 inches wide by 16-1/4 inches high by 6-3/4 inches deep, and each door has a five-pin cylinder cam lock with two keys.
Choose it if a wall-face mounting style is required and the commercial master-lock setup is appropriate. It was selected as the listed six-door surface-mounted alternative to the recessed models. The provided product details do not identify it as a USPS-access cluster box unit, so it may not meet properties seeking that specific format.
Salsbury 3308BLK-U Eight-Door Cluster Box
This Type I USPS-access cluster box is best for properties that need a purpose-built CBU and can use eight customer compartments rather than exactly six. It has eight A-size doors measuring 12-3/4 inches wide by 3-1/8 inches high, two parcel lockers—one small and one large—and a matching pedestal.
Choose this model if parcel storage and the included pedestal matter more than matching a six-door count. It was selected as a close cluster-box alternative because the product is specifically described as a United States Postal Access Type I unit. Its eight compartments make it a mismatch for a strict six-household requirement.
Salsbury 3305BLK-U Four-Door Cluster Box
This Type V USPS-access cluster box is best for a small property that prioritizes larger customer compartments over a six-door count. It has four C-size compartments, each measuring 12 inches wide by 6.5 inches high by 15 inches deep, plus two integrated parcel lockers. The listing says it is approved by the U.S. postmaster general and instructs buyers to contact their local postmaster about installing the USPS-owned arrow lock.
Choose it if larger C-size compartments and parcel lockers are more useful than six separate customer doors. The main limitation is its four-door configuration, which does not independently serve six units.
Buying Guide: How to Choose a Six-Unit Mailbox
Do you need exactly six compartments?
For six individually assigned mail compartments, compare the three 3506 models first. They each have six doors. The listed USPS-access CBUs have four or eight customer doors, so neither matches a strict six-compartment count.
Should the mailbox be recessed or surface-mounted?
Recessed models are intended to fit into a wall opening; the 3506ARP and 3506SRU are the listed recessed options. The 3506ASP is surface-mounted. Confirm available wall space, installation depth, and building requirements before selecting a format.
Which lock arrangement is appropriate?
The 3506ARP and 3506ASP list a master commercial lock as well as individual door locks. The 3506SRU is listed for use with a USPS lock. The 3308BLK-U and 3305BLK-U are USPS-access CBUs; contact the local postmaster about the required arrow-lock installation, as directed in the product information.
Are parcel lockers or larger mail compartments important?
The 3308BLK-U has two parcel lockers and A-size doors, while the 3305BLK-U has two parcel lockers and larger C-size compartments. The six-door 3506 options list individual compartment dimensions but do not list integrated parcel lockers. Compare the intended mail volume and package needs before choosing.
Frequently Asked Questions
Is there a six-door USPS cluster box in this selection?
No. The listed USPS-access CBU options have four or eight customer doors. The three exact six-door options are vertical mailboxes, not described as USPS-access CBUs.
Which listed model has six compartments and a master commercial lock?
The Salsbury 3506ARP recessed model and 3506ASP surface-mounted model both list a master commercial lock with two keys.
Which six-door model is listed for use with a USPS lock?
The recessed Salsbury 3506SRU is listed for use with a USPS lock and is described as meeting USPS-STD-4B+ specifications.
Which cluster box has the larger customer compartments?
The Salsbury 3305BLK-U has four C-size compartments measuring 12 inches wide by 6.5 inches high by 15 inches deep. Its door count is four, not six.