A mailbox support device is provided having an upright post inserted in the ground by means of auger teeth and secured by a stabilizing plate. The support includes a mailbox arm rotatably mounted on the post. The arm is mounted for rotation about the post and can assume a plurality of stable retained positions. The rotational motion is allowed even under extremes of winter weather and permits the mailbox arm to be positioned overhanging the edge of a street or road for easy access while allowing it to be rotated out of the way of oncoming snowplows and other vehicles.