For preventing unwanted information disclosure in a current electronic communication from a sender to a receiver of the current electronic communication, a risk score is assigned for the current electronic communication by a computer system applying an access control model based on historical electronic communications. The model generates the risk score responsive to identities of the sender and receiver and responsive to access control level and hierarchal position of at least one of the sender and receiver. The computer system blocks transmission of the current electronic communication from the sender to the receiver responsive to whether the risk score for the sender and receiver exceeds a predetermined threshold.