By far the best, cheapest ($27) and easiest sensor to integrate into a mailbox, simply mount to the door, the tilt mech is the best for triggering when mail arrives. The Ecolink works just like a door switch, you can have a push notification and even add a text to let you know when the mail man arrives. Nice to also add an alert if the door is left open for more and 5-10 mins (wind might have blown open)…
The nice thing is this unit works on 3 VDC, so instead of using the 2 watch batteries which don’t work well in cold environments like Buffalo NY, I added a battery holder for 2 AA in series. This gives me over 10 times the capacity with a much cheaper battery. I got a plastic electrical box from the hardware store and bolted it on the door of a Step2 MailMaster Plus Mailbox. I packed the AA Battery pack and sensor in a sandwich bag and works great in the cold, holding 100% after a week at near steady 0 Deg outside temp.
To spice up our text alert, you can add a special text ringtone that says “You Got Mail” for free download to your phone book to make it a nice high end integration for under $30.