ROTATING MAIL SLOT

Mail Slot Sleeve can be installed into an entry door to frame and accomodate a Solid Brass Mail Slot, also available from Emtek; Available in Stainless Steel

The rule actually comes from the postal operations manual, and basically what it breaks down to is you are supposed to get permission from

mailslot or mail slot IVES 620 magazine size letterbox plate with standard backplate prevents items from falling in the door and adds durability 7 finishes

mailbox slot cover mail slot hardware for commercial doors and buildings