Spam volumes are still much lower

The shut down of McColo on November 11th resulted in a huge drop in the amount of spam, and volumes are still much lower than they were prior to the shutdown. IronPort, for example, reports that the average volume of spam in September and October was 190 billion messages per day. On November 11th, 153 billion spam messages were sent, but on November 13th total spam volume worldwide was 64.1 billion.