The invention provides systems, mechanisms and techniques for controlling transmission of outbound messages, such as e-mail or other types of messages, onto a computer network from an originator computer system. Connection equipment can authenticate and authorize the connection for the computer user and can capture and map originator network address information assigned to the originator computer system. A quota server can then determine if the message count exceeds the message limit for the originator identity associated with the outbound message Embodiments of the invention control message transmission from a sending or origination point prior to the messages being transmitted on the computer network, resources of a computer network are conserved and these embodiments prevent computer users from transmitting large amounts of outbound messages in excess of the message limits.