If your Outlook spam filter is not working, you should first check that it is enabled and configured correctly. You can do this by opening Outlook, clicking on the File tab, and selecting Options. From here, select the Mail tab and scroll down to the Junk Email section. Make sure that the box for 'Enable Junk Email Filters' is ticked. You can also adjust the level of filtering you would like to apply. If the filter is already enabled, you should try turning it off and then on again, as this may help to fix any issues. If the filter still is not working properly, you could try resetting it by opening the Junk Email Options and clicking on the 'Reset Defaults' button.