Salsbury horizontal style commercial mailboxes are ideal for apartments, condominiums, office buildings, military bases and residential developments. Made entirely of aluminum, 3700 series 4C horizontal mailboxes and 3600 series 4B+ horizontal mailboxes are U.S.P.S. approved and available as front loading units or rear loading units.

Salsbury 3700 series 4C horizontal mailboxes and parcel lockers meet the specifications of USPS-STD-4C. The 4C horizontal mailboxes are required for new construction effective October 2006. The 3600 series 4B+ horizontal mailboxes have been U.S.P.S. approved to the required security upgrades of USPS-STD-4B+. 4B+ horizontal mailboxes are approved for replacement and/or retrofit installations effective October 2006.