SpamMover for Exchange 2007 application can create a folder named Spam in each Exchange mailbox and move any ingoing message that marked with specific mail header by anti-spam software like SpamAssasin, to that folder.
Application is an Exchange store event sink.

Benefits

• You can set up SpamMover on per-mailbox basis or as "store-wide" application, i.e. it will work on each user's Inbox in the certain Exchange mailbox store
• You do not heed to configure Spam rules on each workstation that runs Outlook
• The application is server-centric, so you do not need to install any extra software on the client side
• Even being deleted by user accidentally, Spam folder will be restored automatically when incoming message is received