The mailman personifies how you express and take in information and new ideas. As an Archetype, he can symbolize the channel of communication between the unconscious and consciousness. Often the dream is helping you to open to a new way of thinking or communicating. If he has mail for you - unexplored potential is being activated through the dream. If there is a problem with the delivery - the message can be that you have shut down in some way and are not open to receive important guidance. See also Mail.