I once had a direct confrontation with a resident, I reported it to the police the same day and told my manager after the fact.
He wasn't too pleased, I don't care what he thinks, I've been personally threatened, Royal Mail is not a police force, its my right to have it dealt with, it was dealt with, the police visited the address and told him to wind his neck in or he'll be arrested.
Not heard a peep from him since.
So you go ahead and report it to the police as well, it'll be treated as with any member of the public, Royal Mail won't be helping you. A dash cam footage would be very helpful.