Abstract: The invention comprises a mail access section sufficiently dimensioned for receiving and supporting letters and packages for pickup and delivery by a mail carrier. A mail containment section supports the access section above the ground and receives the mail which is inserted through the access section. The combined length of the access section and containment section are selected so that someone cannot reach through the access section down into the mail containment section. However, the access section is appropriately dimensioned so that mail can be easily placed or tossed into the containment portion. In a alternative embodiment of the invention, a slidable table is located within the access section to provide additional storage space for outgoing packages allowing the structure to operate as a normal, non-security mailbox. In addition, a multi-user security mailbox is described that can be used for multiple residences.