[ 源代码： postfwd ]
软件包：hapolicy（1.35-5）
Balancing and fallback postfix policy delegation service
Hapolicy enables high availability, weighted loadbalancing and a fallback action for postfix policy delegation services. Invoked via postfix spawn it acts as a wrapper that queries other policy servers via tcp connection. The order of the service queries can be influenced by assigning a specific priority and weight to each service.