Why don't dogs like letter carriers?

The origin of behavior
Protective instinct and territorial behavior
Dogs are territorial animals by nature. Their ancestors, the wolves, had to defend their territory against intruders in order to survive. Our domestic dogs have retained this behavior to this day. A letter carrier who regularly enters and leaves the property is often seen as a potential threat. Your dog wants to protect his territory and makes this clear by barking loudly and using aggressive body language.
Repetition makes all the difference
Letter carriers come by almost every day, often at the same time and with the same routine. For your dog, this becomes a ritual to which he becomes accustomed. Every time the letter carrier comes, the scenario repeats itself: intruder approaches, dog barks, intruder leaves. For the dog, it seems as if his barking drives the "intruder" away, which reinforces the behavior.
Psychological aspects
Fear and insecurity
Some dogs react with fear and uncertainty to unknown people or situations. The letter carrier, who usually wears a uniform and often carries large bags or boxes, can appear threatening to the dog. This fear is rekindled again and again by the repeated appearance of the letter carrier.
Lack of socialization
Dogs that have not been sufficiently socialized tend to react suspiciously or aggressively to unfamiliar people. If your dog has not had the opportunity to get to know different people and have positive experiences with them, the sight of the letter carrier can be particularly frightening.
What you can do
Training and desensitization
One way to change your dog's behaviour is through training and desensitization. Teach your dog that the letter carrier is not a threat. You can do this by using positive reinforcement techniques. Reward your dog for staying calm when the letter carrier comes and gradually increase the proximity of the letter carrier to your home.
Socialization
Make sure your dog meets different people and has positive experiences with them. Visit busy places, invite friends and family over so that your dog learns that strangers are not a threat.
Alternative activity
Dogs often bark out of boredom or frustration. Make sure your dog has enough physical and mental exercise. Walks, playtime and training exercises can help to release excess energy and reduce barking.
Conclusion
Many dogs' aversion to mail carriers is a behavior that is deeply rooted in their nature and history. Through understanding, patience and targeted training, you can help your dog to overcome this behavior. In this way, you can ensure that daily mail delivery is more relaxed and stress-free for everyone involved - including your dog.
Remember that every dog is unique and responds differently to training methods. It may take some time for your dog's behavior to change, but with consistency and positive reinforcement, you can make great progress.