Thinking outside the metal (steel) mailbox

Clarifying one thing: the motion sensor at the back of the mailbox is sensing the motion of the door being opened, not the mail being placed within. The door on my mailbox seems to only need be opened 1/4 to 1/3 of the way to trigger the sensor.


He made this system over 25 years ago.
This is what the red flag look like. Open the door and it drops.
I been think of put a Wyze sensor on it too. Then Alexa can say the mail box door has been open. But it came down to the battery and it need to last for a way longer then 4 months.

1 Like

Hello krog83
Below is an idea that may work with the mailbox picture you attached. You may be able to get notices without seeing the mailbox.
Of course, one cannot tell for sure from one picture how it works, but it is an idea. See picture below.

Victor Maletic


The sensors are not outdoor rated and should not be exposed to the elements.

I should have mentioned that.
A small shroud fashioned out of duct tape could mitigate the weather problem.

I see, that would definitely work then. Thanks for the clarification!

1 Like

I used a motion sensor inside the back mine. Works great though mine is made of wood. Probably 75’ from the bridge. If I had a metal mailbox and had connection issues. I would probably use a hole saw to make a 2” hole in the back and cover it from the inside with plexiglass or similar. Could then be painted on the outside to match your box. Mount the sensor on that piece of plastic and cross your fingers.

they cheap also fun how far we can push it to destroy it.
The thing will not kill no one when it rains.

If you pop the battery cover off is seal good. it would take a lot for water to get inside.

Amazon has some nice cases if you can’t print your own.

1 Like

Have you seen open bottom ones with a recessed hidden keeper latch, seized for a Wyze contact sensor sending unit?
Someone in the forum with a 3D printer would be a more likely source, with two case configurations: flat edge (reed switch) vertical or flat edge horizontal. The one I made and posted was a vertical model.
Victor Maletic

1 Like

I forgot to mention that the vertical configuration would fit in @raym64 situation and the horizontal version would work with @kroq83 situation.

1 Like

check these ThingVerse products out …

Hello avincent98122.
I was aware of the 3D printed items that are available, thank you. Others for sure would find your information useful. You and others may want to check out 3D Printers at libraries.
The extended antenna modification of my contact sensor worked for about 6 months until it failed due to faulty soldering. Instead of repairing the broken solder joint, I tried a different approach by extending the magnetic reed switch instead of the antenna. This approach has more useful applications and does not alter the sending frequency of the antenna.
You may be interested in the external reed switch modification I made for my mailbox contact sensor.
Here the link:
Thinking outside the metal (steel) mailbox - 2
Contact Sensor Modified - Magnetic Reed Switch Remote / Outside
I mentioned above that the external reed switch is a more useful modification see the below link for another application:
My Wyze Smart-ish Lock Another Approach

Til later Victor Maletic

1 Like

Hello jon_kelley11.
You may be interested in another way of making a contact sensor work with a metal mailbox. I was able to utilize much of the external antenna system when I switched to the external magnetic reed layout.
Thinking outside the metal (steel) maillbox - 2 and
Contact Sensor Modified - Magnetic Reed Switch Remote / Outside.

Excellent idea…I’m stealing that one!!!

Little tip from personal experience… when your mailbox sensor starts going off annoyingly every few minutes, before you go running around wondering if the battery is dying, the bridge needs resetting, or it’s just broken; go check if you left the mailbox door open. Oops! :blush:


You didn’t do that did you? :sweat_smile:

I had the same problem in spades - all metal mailbox set in brick!

Of course mounted the transmitter in the mailbox.

I made a similar mod, just using a length of wire equal to the original spring (just straighten the spring, cut a wire to the same length). I added a bit for the part that is inside the mailbox and that seemed to work. Figured if I needed to trim to increase range, it’s easier to make the wire shorter. Drilled a hole in the mailbox, used a grommet to keep the wire from chafing and putty to seal. Used some more putty to temporarily locate the new antenna. Since the same putty is holding the mailbox in, it’s pretty durable, so I may just paint it or press sand into it to match the mortar.

Configured the sensor to trigger the camera and turn on one of my Wyze bulbs in my office and change the color to cool white (normally, I have it warmer when it’s on). When the mailbox is closed, I have it change the color temperature back to warm.

1 Like

Hello WidGet.
Nice installation and cleaner looking than mine. I have since changed it to an external reed switch inside the mailbox with the sending unit outside and under the mailbox. Now nothing is visible unless you’re two and a half feet tall and look up at the bottom of the mailbox .
I think your sand idea is very good.
How did you mount the magnet?


I was trying to figure out a way to put the transmitter under the mbx, but I couldn’t work out a way to mount the magnet such that it would pull away from the reed switch given the geometry of my mailbox door.

Turns out the construction of the mailbox door is such that there is a die cast frame around the outside, with an inset metal plate. The rim of the mailbox sits in a groove in the frame (bezel?) for a better seal.

I was able to use the supplied sticky tape to affix the magnet to the metal plate on the door, albeit at 90 degrees from it’s normal orientation to the transmitter. Since it’s a reed switch, there’s some leeway in the orientation as long as you have the proximity correct.

Now we get to see how long the battery in the transmitter holds out.

Sure wish I had my V3 cameras to trigger… :wink: