Mailboxes have not exactly been a hotbed of technological innovation over the last few decades.  Basic mailbox designs have been around for what, forever?  On the 7th day, God rested, on the 8th day, he created the basic design for a secure locking depository box.

Locking mailbox designs basically come in two flavors:

1.  There is the kind that has a narrow slot.  The slot is big enough to fit things like letters and very thin packages, but narrow enough that a human could not reach their hand down to the contents below.  You put the mail through the narrow slot and it drops to the secure locked compartment below.

2.  The kind that has a pull handle connected to a tray.  When you pull the handle on the door, the door is connected to a tray that you put the mail on.  The configuration of the tray blocks anybody from putting their hand in to grab the contents that have already fallen below.  When you close the door, the mail dumps from the tray to the secure locked portion below.

The most popular kind for the US Mail is by far the tray design.  The reason why is because the tray can handle bigger things like packages.  That is why you will notice that almost all the depository type boxes in existence are some modification of the tray type.  From the DHL or UPS box in front of your office building, to the outside book depository at your local library, to the bank depository box where you put your nightly deposits of many thousands of dollars in the bank if you are the owner of, say, Cafe Rio.

Most deposit boxes for video stores are of the narrow slot variety since most DVD's are quite narrow.  Also, most locking mailbox designs for curbside delivery in front of your house are also of the narrow slot design.  The reason why is because these are the easiest to design and make.  The problem with these designs is that they are limited in the size of the package that can go in the mailbox.  For most residential designs, this slot is quite narrow and cannot accomodate most packages.

What homeowners need is a curbside locking mailbox of the tray type!  So, I kept lookinig.  Finally I found a somewhat popular tray type that is on the market already.