The best mailbox for packages is a locking curbside package mailbox with an anti-fishing chute, sized to the parcels you actually receive. USPS carriers can drop small packages through the chute without a key, and nobody can reach back in. Check its maximum parcel size against your usual deliveries, and remember FedEx and UPS cannot use a mailbox at all.
This guide explains how package mailboxes work, what sizes fit which parcels, how locking affects delivery, and when a porch drop box is the better choice.
How a package mailbox works
A package mailbox separates the place where mail goes in from the place where it comes out.
- The intake: a pull-down hopper, a baffle door or a wide slot at the front. The carrier opens it, sets the mail or small parcel inside and closes it. The item drops or slides into the storage compartment.
- The anti-fishing baffle: the hopper or baffle is shaped so the opening never connects straight through to the stored mail. When it is open, the compartment behind it is blocked. That is what stops someone reaching or hooking mail out.
- The retrieval door: a locked door, front or rear, that only you open with a key.
Some designs add a separate rear door so you can collect mail from the yard side, away from traffic. Others include an outgoing-mail tray or flag.
Can USPS deliver to a locked package mailbox?
Yes, as long as the carrier never needs a key. USPS carriers do not open locked boxes and do not accept keys. A locked mailbox must have a slot or chute large enough for your normal daily mail (DMM 508, 3.2.3).
For curbside boxes, USPS-STD-7C sets the minimum incoming slot on locked designs at 1.75 inches high by 10 inches wide (USPS-STD-7C). Anything that fits through the chute can be delivered. Anything that does not fit is left at your door, held for pickup, or handled however your carrier normally handles oversize items.
Can FedEx, UPS or Amazon use my mailbox?
No. USPS rules say a mailbox may be used only for mail bearing postage (DMM 508, 3.1.3), and federal law (18 U.S.C. 1725) makes it an offense to put unpaid mailable matter in a USPS-approved mailbox. That covers private carriers and their drivers. We explain the background in why FedEx and UPS can't deliver to your mailbox.
So a package mailbox catches USPS parcels. For private carriers you need a separate box near the house that is not your mailbox, which brings us to porch drop boxes.
Curbside package mailbox vs porch package drop box
| Curbside package mailbox | Porch package drop box | |
|---|---|---|
| Who can deliver | USPS only | Any carrier (it is not a mailbox) |
| Location | At the curb, on a post | By the front door, porch or garage |
| USPS rules | Must be an approved curbside model, 41 to 45 inches from the road surface to the bottom of the box or point of mail entry, 6 to 8 inches back from the curb | No USPS approval; your HOA may have rules |
| Letters and flats | Yes, mail and parcels together | Parcels only |
| Typical parcel size | Small parcels that fit through the chute | Usually larger, depending on the box |
| Best for | Curbside addresses with frequent USPS parcels and mail theft concerns | Homes that get many FedEx, UPS and Amazon deliveries |
Many households end up with both: a locking package mailbox at the curb for USPS, and a porch box for everything else. If you live in an apartment or HOA with centralized delivery, parcel lockers in the cluster box unit do this job instead; see how parcel lockers work.
Package mailbox sizes vs common package sizes
The number that matters is the maximum parcel size the chute accepts, not the exterior size of the box. Compare it with what you receive. A good reference: USPS-STD-7C uses a Priority Mail box of 8-5/8 x 5-3/8 x 1-5/8 inches and Priority Mail envelopes of 12-1/2 x 9-1/2 x 1/2 inch as standard mail pieces when it tests locked designs.
| Mailbox | Exterior size (H x W x D, per manufacturer) | Max parcel through the intake | Lock |
|---|---|---|---|
| Mail Boss Mail Manager | 11.1 x 10.8 x 20.9 in. | 3.5 in. high x 10.2 in. wide | 12-disc wafer lock, 3 keys |
| Mail Boss Package Master | 16.4 x 12 x 21.5 in. | 4.5 x 4.5 x 10.5 in. | 12-disc wafer lock, 3 keys |
| Salsbury Mail Package Drop | 36 x 14.375 x 23 in. (unit) | Not published; ask us | Front and rear locking doors, 2 keys each, keyed alike |
USPS has also promoted a larger "package-friendly" curbside mailbox class of roughly 13.63 inches wide, 7.75 inches tall at the sides and 12 inches at the center, by 16.5 inches deep (USPS package mailbox page). USPS notes those dimensions are approximate and vary by manufacturer. For more on box classes see our guide to mailbox sizes and dimensions.
Measure the opening, not the box
Customers sometimes tell us their new secure mailbox will not take the parcels they expected. The outside dimensions tell you very little. The opening decides what fits.
- Mail Boss Mail Manager: incoming opening up to 3.5" high by 10.2" wide. Good for mail bundles, prescriptions and magazines.
- Mail Boss Package Master: small packages up to 4.5" high by 4.5" wide by 10.5" long.
- Mail Boss High-Security curbside boxes: thicker steel, but they cannot accept small packages.
Before you buy, pull a typical week of packages from your recycling and measure them. If most are shoebox size or bigger, a porch parcel box may suit you better than a curbside box.
Our picks for a mailbox for packages
Mail Boss Package Master: the most parcel room in the Mail Boss line
The Package Master is built from 12/14 gauge electro-galvanized welded steel with a patented anti-pry latch and Mail Boss's Mail Shield anti-fishing design. It takes parcels up to 4.5 x 4.5 x 10.5 inches and holds about 7 to 10 days of mail. It is marked approved for curbside delivery and mounts on a post with the Fast Trak bracket. It also comes as a complete Package Master mailbox and post, and in double, triple and quadruple post packages for shared driveways.
Trade-off: it is a big box (about 16 inches tall and 21.5 inches deep). Check the look and the post height before you buy.
Mail Boss Mail Manager: small parcels, smaller footprint
If most of your parcels are padded mailers and small boxes, the Mail Manager is the lighter option. Its baffle door accepts mail bundles and small packages up to 3.5 inches high by 10.2 inches wide and prevents fishing. It is made of 14 and 16 gauge steel, holds about 3 to 7 days of mail, and is marked approved for curbside delivery. The Street Safe versions add a rear access door so you can collect mail away from traffic.
Salsbury Mail Package Drop: aluminum, front and rear access
The Salsbury Mail Package Drop is a tall, all-aluminum unit (14.375 W x 36 H x 23 D inches, 50 lbs). Mail goes in through a non-locking front panel, and you retrieve it through locking front and rear doors. It is listed as USPS approved with no master postal lock required, and mounts on a bolt-down or in-ground pedestal. Aluminum will not rust, which suits coastal and snowy areas.
What to look for when choosing a package mailbox
- Max parcel size. Measure the last ten USPS parcels you received. Pick a box whose chute takes most of them.
- Anti-fishing design. Look for a hopper, baffle or shield that blocks the compartment whenever the intake is open.
- Lock quality. A disc-detainer or wafer lock with an anti-pry latch resists casual attacks far better than a cheap cam lock.
- Material. Heavy-gauge galvanized steel resists prying and impact; aluminum resists rust.
- Retrieval side. A rear door is safer on a busy road.
- USPS approval and placement. A curbside box must be an approved model, mounted 41 to 45 inches from the road surface to the bottom of the box or point of mail entry, and 6 to 8 inches back from the front face of the curb (USPS guidelines). Your local postmaster has the final say.
- The post. A heavy box needs a solid post. Call 811 before digging.
Shopping mainly for theft protection? Our guide on how to prevent mail theft covers the rest of the picture.
Package mailbox questions
Can I swap a high-security box for one that takes packages?
Often, if it has not been installed. Returns need to start within 30 days of delivery, an installed mailbox cannot come back, and you pay return shipping, so check the opening size first.
Will the mail carrier put packages in a locked mailbox?
Yes, if the package fits through the slot or chute. Carriers do not use keys, so anything too big for the intake is left at the door or held at the post office.
Can Amazon deliver to my mailbox?
Only when Amazon hands the parcel to USPS for final delivery. Amazon's own drivers, FedEx and UPS cannot place items in a mailbox. Use a porch drop box for them.
What size package fits in a package mailbox?
It depends on the chute. The Mail Boss Package Master takes parcels up to 4.5 x 4.5 x 10.5 inches; the Mail Manager takes items up to 3.5 inches high by 10.2 inches wide.
Are package mailboxes USPS approved?
Many curbside package mailboxes are approved models. Check the listing for the Postmaster General approval, and ask your local postmaster before installing.
Is a porch package box better than a package mailbox?
Neither is better; they do different jobs. A package mailbox takes USPS mail and parcels at the curb. A porch box takes any carrier's parcels but cannot be used as your mailbox.
Shop package mailboxes
See every package mailbox we carry, or browse large mailboxes and locking mailboxes for more room and security. Questions about sizing? Contact us.
******It is always recommended to contact your local postmaster prior to installation. While most of our mailboxes are USPS-approved your local postmaster may have specific preferences in terms of mailbox types and installation location******