How to Change Logging Levels for Exchange 2007 Processes
First, lets check what are the current logging levels for the processes. To do that use the following command in Exchange Management Shell:
To change a logging level use the following command:
Set-EventLogLevel –Identity:”ECIdParameter” –Level “Lowest | Low | Medium | High | Expert”
To get a full list of processes that are with configurable event logging levels go to this website.