Use Microsoft Exchange Server 2003 Load Simulator (LoadSim) as a benchmarking tool to simulate the performance load of MAPI clients. LoadSim allows you to test how a server running Exchange 2003 responds to e-mail loads. To simulate the delivery of these messaging requests, you run LoadSim tests on client computers. These tests send multiple messaging requests to the Exchange server, thereby causing a mail load. LoadSim is a useful tool for administrators who are sizing servers and validating a deployment plan. Specifically, LoadSim helps you determine if each of your servers can handle the load to which they are intended to carry. Another use for LoadSim is to help validate the overall solution.

Important LoadSim should be used only in laboratories that have no connection to the production environment. This tool should not be used in any way in a production environment or an environment that is mission critical or contains important information of any kind anywhere in the network.