About Us

We are an authority website on USPS approved Cluster Box Units and provide a multitude of resources to help you select the perfect Cluster Mailbox for your needs.


Our well-trained staff of customer service representatives is just a phone call away, happy to assist you in any way. Experienced, knowledgeable sales representatives help architects, engineers and contractors determine which Cluster Box to use in their developments. Find CAD drawings of all our Cluster Box Units allowing you to create, download, and print custom specs for your projects in seconds!


Whether you need a Cluster Box Unit for a commercial building, apartment complex or a condominium development, DirectClusterMailboxes.com is your best Cluster Box resource. We are fully committed to providing not only the industry's best CBUs, but also the best customer service, support and resources. We are the Cluster Box Unit experts because Cluster Box Units are all that we do.


Postal Products Unlimited, Inc. has been providing timely delivery of quality U.S. Postal Supplies to the United States Postal Service for over 20 years. As a result of our partnering relationship with the USPS, we have helped the United States Postal Service develop various products line including mailboxes. We actively participate on numerous postal committees. We are a current USPS Mailbox Redesign Committee Member and a USPS Postal Supplier Council Member. In appreciation of the contributions made to the USPS, we have received the following awards:


  • 2009 U.S. Postal Service Quality Supplier Award Winner
  • 2006 Industry Award Recipient, presented at the 2006 National Postal Forum
  • 2005 U.S. Postal Service Quality Supplier Award Winner
  • 1997, 1998 and 1999 Future 50 Awards. Presented by Metropolitan Milwaukee Association of Commerce.

In addition, we are committed to providing the highest quality products to our customers. To meet that end we have gained the following certifications:


  • ISO 9001: 2008 Certified Quality Management System
  • U.S. Postal Service Approved 7B Standard Curbside Mailbox Manufacturer (1812, 1092 Series Residential Mailboxes)
  • U.S. Postal Service Approved 4C Standard Horizontal Mailbox Manufacturer
  • In process of being certified by USPS to manufacture F Specification Cluster Box Unit (CBU) Outdoor Mailboxes
  • United States Postal Service Uniform Certification Program Licensed Personnel Identification Badge Manufacturer. Certification Numbers PRC-3907 and PRC-3908 issued by U.S. Department of the Navy (Nattick, MA).
  • USPS Electronic Data Interchange (EDI) Compliant. Certified in 1997 by USPS EDI Management (San Mateo CA).
  • USPS Postal Service Bill of Lading (PSBL) Creation. Certified by USPS Freight Traffic Management Systems in 2001
  • USPS Branded Promotional Products Prequalified Supplier: November 6, 2008 to Present