Novell Messenger does not require the existence of a GroupWise® system in the cluster, but presumably one has already been set up as described in Planning GroupWise in a Novell Cluster and Setting Up a Domain and Post Office in a Novell Cluster. As part of the process of setting up GroupWise in the cluster, you filled out the System Clustering Worksheet. Some of the information from that worksheet will be helpful as you implement Messenger in your cluster.