Mailborder is an email gateway system designed to filter inbound and outbound email between the Internet and your internal email servers. Mailborder provides a MailScanner frontend, or GUI, that extends the flexibility and usability of the MailScanner core engine. This is accomplished by providing centralized management that enables administrators to easily manage complex policies and rule sets for an unlimited number of domains and users. Mailborder can be deployed in two modes, which are as a Standalone gateway and as a Clustered gateway. Mailborder clusters are a collection of multiple Mailborder gateways operating as a single entity. Each member server pulls its configuration and tasks from the cluster master and thus never has to be directly configured.