Personal boxes emptied by Royal Mail do not have to hold a cypher. Royal Mail write-up boxes created due to the fact 1994 carry the wording 'Royal Mail', Usually above the aperture (lamp boxes) or over the door (pillar boxes). Just before this date all write-up boxes, except the Anonymous https://titusnvbin.timeblog.net/53105627/letter-boxes-australia-can-be-fun-for-anyone