I have NIS 18.5 (2011) and Outlook 2007...
Norton adds a toolbar into Outlook with three buttons "Open Norton AntiSpam" / "Clear Spam Folder" / "This is Spam" / "This is not Spam". The latter two buttons should be enabled/disabled depending on the context.
So if you are browsing the Outlook Junk Mail folder, the "This is not Spam" button is enabled, so you can tell Norton that it incorrectly categorised the selected mail item.
Also, if you are browsing the Outlook Inbox folder, the "This is Spam" button is enabled, so you can manually categorise the selected mail item as spam and move it to the Junk Mail folder.
HOWEVER, if you are browsing (say) a child sub- folder of the Outlook Inbox folder, the "This is Spam" button is NEVER enabled. This is a bug.
I have Outlook set up to use four different e-mail accounts, and there is a rule whereby the mail from each respective account is moved into its own child sub- folder of the Outlook Inbox folder.
Regards,
Andrewfg