Update for Outlook 2003 Junk E-mail Filter (KB911961)
Microsoft released yesterday the February update for the Outlook 2003 Junk E-mail Filter.
"This update provides the Junk E-mail Filter in Microsoft Office Outlook 2003 with a more current definition of which e-mail messages should be considered junk e-mail."
The update is available
here or you can use
Microsoft Update. As usual the update comes with the corresponding Knowledge Base article: