Outlook 2003 Junk E-mail Filter update: June 2005
Microsoft released a new update for the Junk E-mail Filter that provides Microsoft Office Outlook 2003 with a more current definition (according to Microsoft) of which messages should be considered unsolicited commercial email.
The update can be obtained by direct download, using Office Update or using the new Microsoft Update. As usual, you can get specific information about this update in the corresponding Microsoft Knowledge Base article Description of the Update for Outlook 2003 Junk Email Filter (KB896999).