Salsbury recessed mounted 4C horizontal mailboxes and parcel lockers come in 4 different heights – 6 door high, 10 door high , 11 door high and Maximum Height units. 4C recessed mounted mailboxes are available with front and rear loading compartments and can be used for indoor and/or outdoor private mail delivery. Each unit includes a compartment for outgoing mail collection and is labeled “Outgoing Mail.” The outgoing mail compartment includes a weather protection flap and mail slot. All Salsbury 4C mailboxes come with a 5 year warranty and are available in aluminum, black, bronze and sandstone. Private access units include master commercial locks for access doors and parcel lockers.