Mail Boss 7145 2 Box Spreader Bar - Granite double mailbox adapter

In this review the Mail Boss 7145 2 Box Spreader Bar is evaluated for homeowners and property managers who need a sturdy way to mount two curbside locking mailboxes on a single post. The bottom line: this spreader bar is a straightforward, heavy-duty solution that pairs neatly with Mail Boss mounting posts and many existing posts, providing a secure, low-profile way to add a second mailbox. It is best for users who want reliable construction and a clean look rather than a full mounting kit, since this listing is the spreader bar only.

Key Features

• Construction: Built from 12-gauge electrogalvanized welded steel to give a rigid, corrosion-resistant support for two mailboxes.
• Finish: Durable powder-coated finish improves weather resistance and maintains a neat granite appearance over time.
• Compatibility: Designed to work with Mail Boss brand curbside mailboxes including Mail Boss, Mail Manager, and Package Master models for a predictable fit.
• Installation: Includes the hardware needed to attach to a Mail Boss mounting post so most installs are quick when used with matching posts.
• Space saving: Allows two locking mailboxes on one post, saving yard space and providing a tidy, multi-unit setup.
• Versatility: Also compatible with most existing posts, though additional hardware may be required for wooden or non-Mail Boss posts.

Who It's For

The 7145 spreader bar is ideal for homeowners, landlords, and small complexes that already use Mail Boss mailboxes and want to add a second box without replacing the post. It suits anyone who values build quality and a clean, uniform appearance across paired mailboxes.

It is not a complete mounting kit: buyers who need replacement mailboxes or a mounting post should look elsewhere, and those using unconventional posts should be prepared to buy extra hardware to complete the install.

Pros & Cons

Pros

• Sturdy 12-gauge welded steel construction offers long-term rigidity and durability.
• Powder-coated granite finish resists weathering and looks neat next to common mailbox colors.
• Simple installation when paired with a Mail Boss mounting post, with included hardware for that use.
• Compatible with several Mail Boss models for a predictable fit and function.

Cons

• Sold as the spreader bar only; mailboxes and posts are not included, so additional purchases may be required.
• Mixed customer feedback about the included hardware means those using wooden or nonstandard posts may need extra fasteners.

Specifications

Material	12-gauge electrogalvanized welded steel
Finish	Powder-coated granite
Compatibility	Mail Boss, Mail Manager, Package Master models; most existing posts
Includes	Hardware for Mail Boss mounting post
Sold as	Spreader bar only (mailboxes and posts sold separately)
Purpose	Mount two curbside locking mailboxes on one post

Our Verdict

For those who already own Mail Boss mailboxes or matching mounting posts, the 7145 spreader bar is a sensible, well-made way to add a second locking mailbox with minimal fuss. The heavy steel construction and powder-coated finish justify the modest price, though buyers should remember that additional hardware or a post may be needed for nonstandard installations.

Frequently Asked Questions

Does this include the mailboxes?
No. This listing is the spreader bar only; the actual mailboxes and mounting post are sold separately.

Will it fit a wooden post?
It can work with wooden or other non-Mail Boss posts but additional fasteners or hardware may be required to complete the install.

Which mailbox models are supported?
It is designed for Mail Boss curbside models including Mail Boss, Mail Manager, and Package Master, and fits most existing posts when properly adapted.