Consider the postman a field scout for the foreigner or stranger among the nation. In Judeo-Christian law we relate the priestcraft through Masonry. So you are either in or out. Basically you are under the Laws of Moses or its alternate which is the Seven Noachide Laws. If you reside, then you are the nokriy - from nakar - which is from the same root Noach - Noah. I will let you check it out in Strong's for yourselves. Look to Deuteronomy 15:1-3, and 23:20.