How to determine Mailbox Alert Device ID?
You need to know your Device ID to register it. How do you determine it?
[ Short answer for brand new device: separate the sensor parts for 2 seconds. Open WiFi settings on your phone. Your device id is the nnnnn number of the SASensor-nnnnn network. ]
To detemine your device id, it needs to be placed in configuration mode. A brand new device will enter this mode when activated, either by pressing the Sensor button on the circuit board or by briefly separating sensor parts. (Note: a device will also enter configuration mode when cleared: press and hold the clear button and separate the sensor parts briefly, i.e. for a full second).
Separate the sensor parts for 2 seconds. The magnet part must be at least an inch away from the switch part - that's the one with the wires connected to screws if your model is an externally mounted one. This will turn on the MAILBOX Alert and start a 5 minute timer for configuration portal. To reset and start again, simply make sure that the door sensor parts are together for 5 minutes. Then start at the beginning of this step. To skip the 5 minute wait for the restart, you can just press the reset switch on the circuit board as soon as sensor parts are close together again.
Open your phone, go to Settings, and choose Wi-Fi. Under the CHOOSE A NETWORK tab you will see available networks. One of them will be the MAILBOX Alert. It will look like SASensor-000000 where "000000" is the unique Device ID. In the example on the right it is shown as SASensor-2336877. The Device ID is 2336877.