I wanted to share this cool idea with the community. It’s a Bluetooth PostBox Notifier.
I wonder if this could be integrated with the SmartThings Hub? I guess range might be a problem. For houses maybe not a big issues but for apartments might be an issue.
Any thoughts? Is any one else working on such a project?
You can also do this with an open/close sensor. Range might still be an issue though.
I’ve done this with an open closed sensor. Worked really well. I ended up taking it out because it served a better purpose in my kegerator as a thermostat then in my mailbox tellin me when I had bills to pay 
EDIT: I see the one linked works with mailboxes that use a mail slot and don’t open for the mailman. That is interest, albeit unnecessary for me. I wonder how it works, motion sensor or something.