Exchange 2010 brings the option to configure diagnostic logging using the exchange management console, an option that will be made available in exchange 2007 with the release of service pack 2.
In order to use diagnostic logging in 2010, launch the EMC. Navigate to Server Configuration and select the node depending on for which service you want logging increased. In my example, I have only one 2010 server with all three roles installed and hence I can choose any nodes under server configuration and I will get the same option.
Right click the server and click on “Manage Diagnostic Logging Properties”