Since correspondence in a dream represents communication - the mailbox can portray messages in the unconscious that are waiting to be retrieved. If the mailbox is defective, the dream can suggest that you need to pay more attention to inner guidance. If the mailbox is unusual in some way, you may be drawing conclusions when the dream seems to be prodding you to be more open or to take a different view or approach. If the mailbox is full - there may be issues that are blocking you from opening to opportunity. See also Mail.