Abstract: A security mailbox for preventing theft of mail from one's mailbox. The security mailbox includes a container having side walls, a top wall, front and back walls, and a bottom wall and including a compartment inside thereof, and a slot extending in the front wall near the top wall for depositing mail into the container, and an opening in a side wall thereof, and also includes a flag member pivotally mounted to the container, a door member lockingly attached over the opening, and further includes a door member being pivotally mounted inside the container proximate to the slot and having at least one door member which swingingly closes access to the compartment through the slot.