Abstract: A method and system of mediating an exchange of a series of digital messages between parties to ensure compliance with a predetermined messaging protocol associated with a transaction process. The mediation is achieved via an intelligent gateway located between an internal and an external communication network and comprises a component for monitoring messages passing through the gateway and determining whether the messages comply with or deviate from the predetermined messaging protocol, which may be coded in a global description language. The monitor may act passively and provide a notification of the degree of compliance or may actively block non-compliant messages. A mechanism is provided for replaying and fixing non-compliant messages. A system comprising several intelligent gateways includes a router for routing messages to a particular intelligent gateway according to destination.