You can configure Symantec Message Filter for high availability and performance. Symantec Message Filter is licensed on a per-user as opposed to per-server basis. Therefore, you can install the software on as many servers as is necessary to handle your needs. The client supports round robin load balancing and fails over to secondary servers or tertiary servers for redundancy. The filtering daemon is multi-threaded, so it makes optimal use of multi-CPU systems.
High availability deployments typically use two Symantec Message Filter Servers. Some customers that use dedicated systems have numerous MTAs installed with the Symantec Message Filter client. All of these MTAs point at a pair of Symantec Message Filter servers. To provide redundancy, the Symantec Message Filter client configuration includes the IP addresses of both available Symantec Message Filter servers.
Figure: High availability scenario illustrates the high availability scenario for Symantec Message Filter deployment.