Typical Setup...

E-mail Management Server 2006 (ES2006) is an extremely powerful and flexible application allowing for granular content management of both attachments and messages stored in MAPI based information stores like Personal Folder Files (PSTs), Exchange Server Mailboxes and Exchange Server Public Folders.  Completely customizable, ES2006 can be configured to analyse, copy, move, delete or archive messages and attachments easily via manual processing or automatically during a predefined schedule. 

Moreover, the implementation of E-mail Management Server 2006 is quick and simple utilizing existing technology you have already deployed.  Below is a diagram of a typical ES2006 implementation.