Mail Drop Slot & Receptacle

The clear rectangular opening in the outside slot plate must be at least 1-12 inches wide and 7 inches in length · The slot must have a flap, hinged at the top

However there is a slot for mail on the back that is accessible even when the boxes are locked According to Postal Inspector Patricia

usps mail slot Cluster Mailboxes · 4C Horizontal Mailboxes · 4B Horizontal Mailboxes · Vertical Mailboxes · Locking Mailboxes · Mail Package Drop & Collection · Letter Drop Boxes

ninja 777 slot mail The lip over the letter slot often broke, letting in rain and snow By 1891 the Post Office Department had over 48,400 letter boxes of various