Prior to USPS mailbox regulation changes in 2006, horizontal mailboxes were the standard for many large multifamily residential and business mail delivery applications. However, these time-tested mailboxes may now only be used in direct one-to-one replacements in facilities with U.S. Postal Service mail delivery. When initiating a replacement or renovation project - it is always a good idea to get the approval from your local postal authority before altering the mail system in your building; but in general, if your project is not disturbing the wall the mailboxes are already mounted in, then replacing old mailboxes with a product similar in style is typically acceptable. Any adjustment to the rough opening in the wall will require new STD-4C compliant mailboxes.
Horizontal mailboxes are still an excellent mailbox solution for any private delivery installation such as university dorms, internal business office distribution, or a myriad of other private applications.
1400 Series FL USPS 4B+ Approved
Florence 4B+ front-load horizontal mailboxes (1400 series) are a great solution for indoor installations as these traditional-style mailboxes were most popular in apartment complexes, and university/military housing. The standard for decades, the 1400 horizontal mailbox series is only USPS Approved when being used as replacement units for existing installations.
1600 Series FL Private Distribution
A favorite of University housing managers due to the ability to provide a lot of compartments in a small space, this indoor solution helps keep your mail area organized.