Getting digital mail when you have analog mail!
A reed sensor is connected to a LILYGO T8-C3 ESP32-C3 dev board. When the reed sensor is opened (the postman opens the lid of the mailbox), it connects to WiFi, sends an email, and goes to deep sleep again.
For a full devlog about this project, check my website.
To use this in your own setup, make a copy of the config.example.h file. Rename it to config.h. Change the contents of the file to your own needs.
I fitted this project inside of a small lunchbox of approximately 11 x 8 x 5cm.