Every owner or occupant of lands lying within the Township adjoining a public roadway is prohibited from placing or allowing to be placed within five feet of the road right-of-way any obstruction, including, but not limited to, fences, walls, signs and pillars. This section shall not apply to signs installed by the Township, federal, county or state governments, utility poles, fire hydrants, or mailboxes installed in accordance with this Subsection B. However, under no circumstance shall a mailbox be installed in or about a wall, pillar or other permanent structure except by a post or pole as described below. Mailboxes shall be set on a single wood post that is not greater than four inches square or has a diameter of 4 1/2 inches or less, or affixed to a metal pole not greater than two inches square or has a diameter 2 1/4 inches or less. All such mailbox posts must be set back 12 inches from the edge of pavement. Also, all mailboxes must be installed in accordance with the rules, regulations and standards established by the United States Postal Service.