The Nimrod project will develop next generation commercial secure messaging systems based upon the technology deployed in military messaging systems. Military messaging systems require solutions that are comprehensively evaluated to the Common Criteria Evaluation Assurance Level 4 standard. Typically these systems combine a messaging firewall that allows the exchange of e-mail between networks of differing security levels or with conflicting security policies and a high-assurance Internet e-mail and X.400 boundary checkpoint designed to enforce absolute policies in environments where security is paramount. Initial market analysis has shown a significant opportunity to create an enterprisescale secure messaging system for commercial deployment where there are appropriate audit and/or operational requirements. This new product will require a new architecture and many functional additions: with appropriate specification and engineering the same system will be applicable to both commercial and military deployments. This new secure messaging system will provide three significant innovations: (a) The ability to filter a broad range of content types – in particular voice and video artefacts attached and/or referenced by the associated emails and Web Service traffic in the form of SOAP messages and the associated XML data and attachments. Filtering will be undertaken in real-time to ensure a system latency of 1s for a message load of 8-10 thousand messages per second; (b) A flexible and remote administration capability such that the secure email system can be easily managed (including the ability to download new versions of the system, to install new content plug-ins, proxies and the reconfiguration of the business rules to be applied to the message stream filtering; and (c) Enterprise Adapters to provide business process and workflow integration so that the appropriate processes and security policies can be deployed/enforced within an enterprise system.