User Useage Tracking

We are running Exchange 5.5 with Outlook 2000 as the mial client and we would like to track or log a single users e mail activities. I have poured through my Exchange manuals, and have not found a good way to do this. Ideally we would like to knowhow many messages are sent a day and to whom they are sent. Does anyone know how I can do this without sifting through logs? Our server handles over 1100 messages a day and I am afraid trying to mine logs for the info we need would be a huge task ans drain on the server resources.