I have just enabled the DNS Anti Spam plugin to catch comment spam that isn't stopped with the bayesian filter. This plugin does some dns checks to determine if:
- The ip address is from a known spammer on sorbs.net, spamhaus.org, or dsbl.org.
- The title, body text, or the username has a url that is known to be sent out as spam at surbl.org
- The url is known to be sent out as spam at surbl.org