Why am I getting messages labeled [spam] in my outlook inbox?

[Norseone]

These items are not going to my junk mail folder, but rather being labeled in
my inbox. Messages are forward from Yahoo mail. There is no indication that
Yahoo thinks these are spam, and generally, they are not. I am using Outlook
2003

 

[Frankster]

Your email server or a AV/Spam program is changing the subject to [spam]
because it is spam according to their filters. Which may not match the OL
spam criteria.

-Frank