Systems and methods for message mediation and verification. A system may include at least one processor configured to maintain a plurality of interconnected boards, wherein a first group of at least some of the plurality of interconnected boards include items that contain external contact addresses, and wherein a second group of at least some of the plurality of interconnected boards omit external contact addresses; monitor, via a mediator overlay on the enterprise messaging system, contact addresses of incoming messages; compare a contact address of an incoming message against a repository of addresses associated with the first group of at least some of the plurality of interconnected boards; in response to a match between the contact address of the incoming message and at least one address contained in the repository, generate at least one primary duplicate of the incoming message.