It only takes a second to click on the spam and rate it 1 star. It is also valuable for the board to give 4-5 stars to the good posts. This board is pretty stingy with the stars. Take back control of your board.
You need to be logged in to Yahoo to set star ratings. Then all you need to do is click on the row of stars below the message - click the leftmost one to rate it at one star, and the rightmost one to rate it at five.