Abstract: The present invention allows complex messaging configurations (e.g., server clusters) and messaging activities to be simulated in a single test. A server cluster having two or more mail servers is provided. Each server in the cluster is assigned one or more mail databases that are also replicated to the other servers in the cluster. Thus, each server has a copy of every mail database. Mail clients are then assigned to specific mail servers (e.g., 50% of the mail clients are assigned to mail server “1,” 50% of the mail clients are assigned to mail server “2”). The present invention will drive a messaging workload against the servers (in a single test) that will simulate the type of messaging activity that is typically experienced when the servers are in actual use within an organization or business.