Messaging Server can be configured for failover. Use Chapter 3, Configuring High Availability, in Sun Java System Messaging Server 6 2005Q4 Administration Guide as a guide to installation and configuration.
To install the necessary packages, run the Java ES installer on each node, installing Messaging Server and the HA Sun Java System Messaging Server subcomponent of the Sun Cluster Agents component. Select the Configure Later option.
When specifying installation directories, use a location on the cluster file system for Messaging Server. During configuration, place the configuration and data on the cluster file system.