Modern Mail Slots - Standard & Large Sizes Available

What Is a Mail Slot?

A mail slot is a narrow opening, usually cut horizontally through a door or exterior wall, that lets a carrier drop mail straight into your home or business. You might also hear it called a letter box, letter plate, or letter slot. It delivers mail behind a locked door instead of leaving it exposed at the curb, which is why so many older homes and downtown storefronts still use one today.

If you'd rather not cut into your door, wall mount mailboxes are worth a look too.

Door Mail Slots vs. Wall Mail Slots

Most buyers land in one of two camps: cutting the slot into the door itself, or recessing it through an exterior wall. Door mail slots are the classic setup: the slot goes right into the door, sized to match its thickness, and works well for standard walk-up delivery. A wall or through-the-wall mail slot uses a front and rear plate recessed into the wall, so you're not modifying the door at all, which makes a wall or through-wall slot a good fit when cutting the door isn't an option. Our European Home stainless steel mail slots use a two-piece front-and-rear design that can be recessed into a wall. The manufacturer recommends a standard door installation for best performance, though, and wall mounting requires custom work.

Mail Slot Sizes: Letter, Magazine & Package

Measure the rough opening, not just the visible plate, and check what your door or wall thickness can accept. Slots come in three tiers: letter for daily mail, magazine for catalogs and larger envelopes, and large or deluxe for small packages if you get frequent deliveries. The Salsbury Standard Magazine #4045 runs a 13" x 3-1/2" plate with an 11-1/4" x 2-1/2" rough opening as a mid-size example.

Our European Home stainless slots come in two sizes, 11.8" x 3" (small) and 15.7" x 3.9" (large); the large is our widest stainless option, with letter and magazine capacity.

A vertical mail slot suits tighter door layouts. Shop our full range of mail slot sizes to find your fit.

Our Mail Slot Materials & Finishes

Solid brass is the classic choice for a brass mail slot or antique look: heavy, durable, and available in antique, brass, and chrome finishes. Stainless steel gives a cleaner, modern look with strong rust and weather resistance, which is what our European Home line is built around. Spring-loaded flaps seal out wind and rain, and some models include an inner trim or hood for extra protection.

Our Streetscape Executive brass mail slot is a solid example of the traditional route done well. Shop our brass and stainless mail slots to compare finishes.

Single-Flap vs. Double-Flap Mail Slots

A single-flap mail slot has one exterior flap and keeps things simple and budget-friendly. A double-flap mail slot adds an interior flap, which seals better against weather and adds privacy. Spring-loaded flaps stay shut and quiet in windy weather; gravity flaps rely on their own weight to close.  

Are Mail Slots Secure? Covers & Anti-Theft Tips

Generally, mail slots are safe, but "mail fishing" (someone reaching through to grab mail) is a real, if uncommon, concern. A mail slot cover or interior hood, plus a mail catcher basket, cuts that risk significantly, and positioning the slot away from your door lock or deadbolt removes the bigger worry. An interior cover also helps with drafts.

 A mail slot still delivers behind a locked door, which curbside boxes can't offer. If security is a bigger priority, our mailbox lock and security guidance covers additional options, including locking wall-mounted receptacles.

How to Install a Mail Slot

Installing a mail slot in a door is a manageable weekend project: 

1. Mark the opening

2. Cut it to size 

3. Fit the exterior plate

4. Attach the interior plate from the back 

5. Secure everything with the included hardware. 

Door and wall thickness varies by mail slot, so measure yours before ordering; our team can help match you to a fit. 

Wall mounting for our European Home stainless line is a custom installation rather than a standard retrofit, since it needs a rear plate or receptacle and a finished opening behind it.

For full USPS delivery requirements on new installs, our USPS mailbox compliance guide walks through what applies to door slots.

Mail Slots & USPS Delivery

A mail slot is built for through-door residential delivery, and our Salsbury Standard mail slots are noted by the manufacturer as suitable for USPS residential delivery. Always confirm any delivery-mode change with your local postmaster first, since approval isn't automatic everywhere, per USPS mailbox installation guidelines.

Weighing a mail slot against curbside or cluster delivery instead? Our residential mailboxes selection covers that.

Why Choose Our Mail Slots

We carry brass, stainless steel (European Home), and premium Streetscape mail slots across both door and wall mounts, with real dimensions and finishes in stock and fast shipping on every order. Our team can help you match finishes and get the right mail slot on the first try. Browse all wall mount mailboxes if you're weighing a wall install too.