I have a camera on my front door with a mobile app to view it. I recently had out mailman do exactly this (while I was home and only a few feet from the door).

I have a camera on my front door with a mobile app to view it. I recently had out mailman do exactly this (while I was home and only a few feet from the door). I had to chase him down and he told me flat out that he had knocked, waited and I wasn't home. I showed him the camera footage and I've never had a problem since (and I'd have weekly problems with this beforehand ).