Upgrading a 4-Unit Rental Property to Locking Mailboxes for Security and Long-Term Durability
Mail theft continues to be a growing concern for rental properties across the United States. For property owners and managers, unsecured mailboxes can lead to tenant complaints, maintenance requests, and lost mail issues.
Many older multi-unit mailbox setups were never designed with modern security in mind. Thin materials, unstable mounting systems, and non-locking mailbox doors leave tenant mail vulnerable to theft and weather exposure.
For this 4-unit rental property in Bellingham, the existing non-locking mailboxes needed to be upgraded to comply with BMC 6.15.050 a city ordinance requiring locking mailboxes for rental properties.
The property manager wanted a secure, low-maintenance solution built to last for years with minimal upkeep.
Removing the Existing Non-Locking Mailboxes

The original mailbox setup consisted of older non-locking mailboxes that no longer met current rental property security requirements. We began the project by completely removing the existing mailbox system to prepare for a more permanent installation. Because multi-unit mailbox systems place significant weight and stress on mailbox posts, proper structural support becomes extremely important during installation.
After digging two post holes, both steel posts were secured in concrete to create a rigid foundation to resist movement, leaning, and long-term wear.
Once the mounting system was fully secured, we fastened four Mail Boss Mail Manager high-security locking mailboxes to the spreader plate.
The final result is a sturdy, secure, and professional-looking mailbox system designed specifically for multi-unit rental property use.
Why Mail Boss Locking Mailboxes Work Well for Property Management
From a property management perspective, mailbox security is important but so is ongoing maintenance and key management.
One advantage of the Mail Boss Mail Manager system is the simplicity of replacement key ordering.
Each mailbox key includes a unique serial number that allows replacement keys to be ordered directly from the manufacturer quickly and affordably. Replacement keys are relatively inexpensive, eliminating the need for:
- Locksmith services
- Lock drilling
- Full lock replacement
- Third-party coordination
For property managers handling tenant turnover, lost keys, or maintenance coordination, this creates a much simpler long-term ownership experience.
Why Proper Multi-Unit Mailbox Installation Matters
Approximately 120 pounds of locking mailboxes are mounted on the finished setup. A multi-mailbox installation carries substantially more weight and stress compared to a single residential mailbox setup.
Proper installation helps:
- Prevent post movement and leaning
- Improve long-term durability
- Reduce maintenance
- Support heavier locking mailboxes
- Improve curb appeal
- Increase tenant security
Benefits of Locking Mailboxes for Rental Properties
Locking mailboxes help:
- Reduce mail theft
- Protect sensitive tenant information
- Improve tenant confidence
- Reduce complaints related to stolen mail
- Improve compliance with local ordinances
For property managers, investing in a durable locking mailbox system can also reduce future maintenance headaches and replacement costs.
Final Result

This project transformed an outdated non-locking mailbox setup into a reinforced multi-unit locking mailbox system built for long-term durability and low maintenance.
The property now has:
- Four high-security locking mailboxes
- Heavy-duty steel post reinforcement
- Improved tenant mail security
- Reduced maintenance concerns
- Compliance with Bellingham rental property requirements
For multi-unit property owners and managers, properly installed locking mailbox systems are one of the simplest upgrades that can improve both property security and long-term reliability.
Want to see the installation process from start to finish?
Watch the YouTube installation video here:
https://youtu.be/PbH8LNF5WgU
The Mail Boss Mail Manager mailbox, heavy-duty steel mailbox post, and four box spreader bar used in this installation are available through our online store:
Mail Manager
Heavy Duty Steel Post
Four Box Spreader