If you are in fear due to these anti-social activities you could consider fitting an external locking wall-mounted letterbox and replacing the standard letterbox within your door with a solid metal blanking plate. Alternatively, you may wish to consider fitting a sash jammer on the inside of your door next to your letterbox flap to enable you to prevent it from being opened, other than when your post is due.
Keep gates closed, maintain fences around your property and consider fitting ‘dusk to dawn’ lighting (get one with an LED bulb as they are much cheaper to run) to deter people from entering your property.
