It is extremely simple, requiring no holes be drilled, and requiring {TAIL ~ only one small downwardly slanted cut} be made in the rearward flange of {HEAD ~ the mailbox door} 
It is extremely simple , requiring no holes be drilled , and requiring { TAIL ~ only one small downwardly slanted cut } be made in the rearward flange of { HEAD ~ the mailbox door }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD