Using Exchange 2000/2003 Server, you can enable Message Journaling function on a per-mailbox store object basis. It means that feature will affect each mailbox belonging to the given mailbox store. See MS article named How to Enable the "Message Journaling" Function for an Exchange Server Mailbox Store" for details.
This application allows the Exchange administrator to set Message Journaling on per-mailbox basis. He can, for example, archive the messages addressed to the only user or to the group of users. Also for any given mailbox only ingoing messages or only outgoing messages archiving (journaling) can be set.
The application is an Exchange store event sink.
You can set up journaling of any subset of Exchange mailboxes
You can journal only incoming or only outgoing messages