SPAM misidentified?

When I right click any of the emails in my inbasket and folders, slide down to Norton AntiSpam, it slides out saying 'This is Spam'.  When I right click any of the emails that ended up in the Norton AntiSpam Folder, it says 'This is Not Spam'.  Totally backwards!  I have Norton Security Suite from Comcast.  I run WIndows XP and DL my emails to Outlook Express.

I stumbled on this because I've had a few incidents lately where my emails were not received.  I got suspicious of my outgoing email not going out, so I sent myself one of the suspect emails to my other email address (I have one personal and one business), and swItched over to my other user mail and did not receive it.  I signed on to Comcast to see if it was in the inbasket there, but it wasn't.  So it apparently never left my computer.

So that's when I right clicked my sent email and it said it was spam.  That's when I started right clicking a bunch of my 'sent' emails in the sent folder and they all said they were spam.  But most of them got responded to, so I know most of them went out.  BUt one that didn't caused me to miss an appointment.

So that's when I started looking at everything in the email program, all the folders, either email address, and they all say 'This is Spam', except for the ones in the Spam folder.  CRAZY.  What do I do?

I never changed any security settings.  Could a recent automatic update be the culprit?