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