MSExchangeTeam blogged yesterday about Journaling in Exchnange Server 2007. Basically e-mail jornaling is the ability to record all all e-mail activity in an organization.
Read at source: http://msexchangeteam.com/archive/2007/06/22/444296.aspx
You can also validate an article that explain that functionality at msexchange.org site: http://www.msexchange.org/tutorials/Exchange-Server-2007-Using-Journaling-Rules.html
Technorati : Exchange 2007, Journaling
Del.icio.us : Exchange 2007, Journaling