Mailbox open/close sensor

My mailbox is quite a long way from my house, and I have a knee with a mind of its own, so to avoid needless walks I thought a multipurpose sensor would work great. It could detect when the mailbox opens and closes. But my mailbox is metal in a brick enclosure. The problem is the metal mailbox acts like a shield, so the signal is bouncing around inside the mailbox and not going anywhere. I don’t want to mount it on the outside of the door because these aren’t moisture proof. There should be some Thing made that works as a mailbox sensor for a metal mailbox. I have thought of adding an antenna but that would involve drilling a hole in the mortar and the metal mailbox, and finding where to connect the antenna to on the sensor. And since the sensor would be on the door, the wire would have to be located near the hinge end and be very flexible.

I am open to any suggestions.

Thank you

There are a lot of maibox alert devices on that claim to work at long distances. I don’t know if any claim to work with ST; but I know some of them can be adapted to work with ST. The Dakota Alert driveway monitor I adapted works very well with ST.


What about a Shock Sensor like from Monoprice? Or even a Garage Tilt Sensor.

Place it on the inside of the mail box door, when the mailman tilts it open it sends a signal. And because the box is open it is free to send to your hub.

Another thought, you could also take a door/window sensor, put the magnet part inside the mailbox and place the battery side on the door.

what is the distance?

I agree with the Dakota 2500 series suggestion. I use that with a MimoLite for outside gate open/close monitoring plus yard motion sensors. Works like a champ.

Range says 1/2mile. Gets great reviews online. I can certainly confirm it works fab in my setup.

The Dakota Universal Motion Sensor has a wired external connection so you can hook it up to any standard magnetic sensor.

The Dakota base station has wired relay output that closes/opens upon motion trigger which hooks up to a MimoLite (configured as a generic Zwave Motion trigger).

You can check the project report section of the quick browse lists in the community – created wiki. There’s a list there for mailbox notification projects which might give you some ideas. This is a fairly common problem, and people have taken a number of different approaches to it. :sunglasses:

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With my bad knee, it seems like miles but it is probably 200 feet.

I temporarily attached the sensor to the outside of the door after adding it as a thing and verifying indoors that it did work. At first it didn’t work on the outside of the mailbox door, but after I added a few smart bulbs as repeaters to the post lights in between the house and the mailbox, it was recognized right away.

I can see where you are going with this, and I thank you for your forethought. After spending all that time and finding out it was out of range would not be good.

To : JDRoberts

Thank you. I will head there.

“You don’t know what you don’t know” is one of my oft-used quotes in situation like this.

To :johnon:

This seems like a possibility. I will investigate it.
Thank you

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This project has been moved down the list due to my current project to have an announcement over a smart speaker when events occur.

I am going to see if it works as a garage door sensor and when the mailbox door is closed, it should show the change right before the door closes and blocks the signal. All this is being done with Velcro so no unnecessary holes are drilled.

I sincerely appreciate all the replies. Seems I’m not the only one who thought of this. Kick me for not searching before I hollered.

I finally got time to work on this some more. The multipurpose sensor is attached to the INSIDE of the metal mailbox door with super sticky tape for testing purposes.

The mailman came today at exactly 4:35 pm. The sensor detected the door opening and closing. The logs in the SmartThings app agree. I can only presume the signal is being sent while the door is opening and closing. Once the door is closed, the signal cannot pass through the metal mailbox. But once the door is open, the signal is free to escape.

I have the sensor set as a garage door sensor.

This is only the first day of this test. Updates will be forthcoming if necessary.

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After a few days, this idea does not work. For some reason it did at first, but not anymore.

I mounted the Samsung multipurpose sensor on the outside of the mailbox door and told SmartThings it is a garage door sensor. When the door is opened the log shows “acceleration is active” then “acceleration is inactive” after the door is closed but this is not enough to trigger anything. Going through the various options in automation I see nothing that will say the door has been opened or closed. I have also tried not telling it is a garage door sensor. Any idea what I am missing?


I had attempted to use a Samsung Multipurpose sensor with the same setup. Was not getting triggered alerts, was getting false alerts on occasion, and generally was unreliable. Had two other of the same multipurpose sensors setup on two garage doors for open/close sensing and they work 100% as expected without false alerts.

Ultimately, what I think the issue is/was - the sensor wants a slower pace of tilt from closed to open to trigger properly and the garage setup is optimized to do that when setup that way within the app. The mailbox door is generally “thrown” open and closed by mail carrier and 90% of the time it just did not trigger properly.

Attemped to also use a very small motion sensor (Iris) in the back of the mailbox and that also did not work as expected. I ended up using that inside after the mailbox failure and the sensor works great, so it was not a sensor issue.

There are people who setup antennas, larger batteries, external enclosures, etc. It’s too much work for a mailbox sensor for me. Have enough false alerts with a fence gate sensor in a weatherproof box (and the terrible battery life indicator in low temperatures) that really made me reconsider using the sensors outdoors (even in a weatherproof box).

If a better solution is released I may give it a shot, but for now I’d look into the radio-based mailbox sensors and attempt to connect to an open/close sensor using the internal contacts.

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One thing to note with range issues and adding new Zigbee or Zwave repeating devices to improve your coverage. To ensure your mesh is rebuilt in the most efficient manner (devices choosing best partner to connect to) you should rebuild your Zigbee or Zwave mesh:

  • Zigbee: Unplug hub, remove batteries if any, wait 20 minutes, plug back in.
  • Zwave: Perform a Zwave repair, either from the SmartThings mobile app, or from the IDE. I prefer the IDE as Zwave repair from the mobile app doesn’t work consistently for me. I start the Zwave repair at night as I’m going to bed in case it takes a while, and to minimize my use of the while the repair is going on.

i was using ecolink door sensor on inside of metal mailbox… it was spotty. i now switch to their new zwave plus ones . workes perfectly about 100 feet from front door.


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Lgkahn, this is similar to the Samsung multipurpose sensor. This design works well on my patio door, since both the sensor and magnet are used. For my mailbox sensor I did not use the magnet and told SmartThings that it is attached to a garage door, so it has the capability to detect horizontal from vertical. Unfortunately, according to smarthomer, the multipurpose sensor needs a gradual change from vertical to horizontal, and vice versa. The mailbox door is opened and closed within a few seconds, whereas the time from when the garage door is open to the time it is closed is considerably longer.

I had more hair before I began this smart addiction. :slight_smile:

Got an idea from another thread on here… used a linear/gocontrol door/window contact sensor. The key is the device supports an external wired contact sensor, so I bought one for <$5 on amazon, hooked it up to the terminals and then ran that wired sensor inside the mailbox… leaving the z-wave transmitting contact sensor on the outside. Success! No more metal box blocking the signal (I, too had tried with a tilt sensor inside before.)

Successful in my tests so far, we’ll see how it holds up in real life!

Closest repeaters are a z-wave switch in my garage (door closed,) z-wave switch inside front door of house (on other side of bricks + closed door) and one outdoor z-wave plus repeater I use for a pipe heater. However, the sensor I am using is not z-wave plus… so suppose if I still have issues I bet if I upgrade it might get it the extra little bit of range it needs to talk to the outdoor repeater that little bit better.

I installed the sensor body facing this way (obscuring useless LED) because I’d rather remove the slotted battery cover than try to pop the entire device back onto the battery cover and because the z-wave antenna is on this side, which I figured would be better if it stuck out from the brick more. Secured with 3M VHB, not too worried about it going anywhere.

With this thing 1" higher under the metal of the mailbox bottom) it did NOT work. I would imagine it’d be a lot easier without a brick + metal mailbox… but if I can get this working surely others can!

As you can see you can’t really see it from most angles, so not worried about looks too much. I wasn’t about to just stick it anywhere else on the brick, though. I think this is a good compromise.

Have had a bit of mail theft in the area for quite some time, so look forward to seeing if anyone is snooping around by having the exact timestamps to reference on my security cameras. (Plus I’ll know if the mail has come!)


I also have a metal mailbox in a brick enclosure. My ideal end to this was to get a text message when the mail was delivered, and to turn on the Aeon Labs Doorbell Gen5 with a custom sound. As it is, I can check the log to see if the mailbox door was opened.

try the ecolink zwave plus sensors i recommend they will work in that configuration if they work inside my metal mailbox 100 feet from my house…

i use .the stock notify me when smartapp to send messages when the mailbox is opened… ie mail arrived.


Thanks for the recommendation. I ordered an Ecolink Z-Wave Plus Garage Door Tilt Sensor so hopefully this is the same sensor you have.

You say it works INSIDE your metal mailbox? How does the signal radiate?

Same company but I use plain door sensor

Thanks for the recommendation. I ordered an Ecolink Z-Wave Plus Garage
Door Tilt Sensor so hopefully this is the same sensor you have.

You say it works INSIDE your metal mailbox? How does the signal radiate?