I bought this since our mailbox is a ways from our house and we never know when/if we get mail. So far it triggers and alerts us while the mailman is STILL at the box. I was shocked on how fast it reacted to be honest. We can hear the alarm we set in a window facing the box throughout the house and the app alerts are just as fast.

The ONLY issue is the app is missing a feature to pause alerts throughout the day. If you put mail into the box in the morning for pickup, the mailman delivers mail, and then you open the box to get the mail....you will get THREE alarms and alerts. The app needs a way to PAUSE alerts/alarms easily for like 2,3,5 minutes for when you need to open the mailbox for various reasons. It only needs to go off when the mailman opens it or strangers.

Our mailbox is up a hill from us, so it’s nice having this alarm to let us know when we actually have mail. I wish you could make custom alarm tones though. It has multiple types of chime sounds, but I would prefer one thing that didn’t sound so much like my doorbell.

We have four mailboxes on the same beam and it will beep when the one next to me opens their box. Otherwise, it works great. (No, they aren't opening mine)