Dog bit postman through letterbox

Hi. It’s traumatic to be bitten by a dog and, apart from the shock element, there is the worry that an infection may result from the bite. For you to assess the postman’s trauma and worry by the “amount of blood” on his finger is not fair, and to me suggests you’re more interested in justifying yourself than accepting responsibility for the fact that you own an animal which inflicted an injury on a non-trespasser going about their day-to-day business.
Some mail deliverers are told that it is important to ensure that mail is fully pushed through the door so that uncollected mail doesn’t attract potential burglars who are alerted to the fact their is no one home.
So it is conceivable that a conscientious worker may push his fingers passed the inside of the letterbox to ensure the mail has gone fully through - especially if you have letterbox draft excluders.

Every homeowner knows to expect that postmen will call on their property. So every dog owner should consider the risks that their animals pose in these scenarios.

Your defence that the dog usually barks and that he’s never done it before only go to the point that you had (perhaps understandably) become complacent about the risks. Perhaps your dog didn’t bark this time. Perhaps the postman is hard of hearing. What else are you suggesting: that the postman thought “Hey, sounds like there’s a vicious dog behind this door, I’ll offer it my fingers!”?

I don’t mean to sound unsympathetic. You are doing the right thing by putting a parcel cage on your door. I’m not saying you’re uncaring. But the point is that you own an animal that bit a person. You should have taken all measures (including getting a warning sign and a parcel cage) to ensure that your animal doesn’t pose a threat to people who are performing a service for you.