Here is a LoRa mailbox sensor project for HA.
I’ve actually been working on this one the last couple of weeks. You don’t need really any programming experience for it. His particular hardware setup requires a fair bit of work because his project is trying to save a lot on battery life. If battery life is not so much an issue, I would think you could buy an off-the-shelf ESP LoRA board instead of using his hardware setup and just tweak his mailbox sensor code. Its very simple.
Here is a companion video to show what the software setup is like.
