Comment spam is a problem that’s raging out of control and WordPress blogs have become the spammers’ favorite target. The default install of WordPress makes it incredibly easy for robots and spiders to submit garbage comments laden with spammy links at a constant rate.

It’s almost impossible anymore to handle these comments without the help of a plugin.

The most popular spam fighting plugin, by far, is Akismet by Automatic. This plugin has always been my weapon of choice against spam comments because of its clever use of a centralized database.

In short, Akismet collects and categorizes comments from every blog running the plugin. It then uses rules based on the comment’s content and also how other blog owners have judged similar comments to decide whether or not the comment is spam. Akismet even works on trackbacks and pingbacks.

Akismet requires an API key from WordPress.com to run so you’ll need to make an account there first. That’s the only big hurdle in the installation and it’s worth it based on how well Akismet performs against spam. Your API key can be found on your WordPress.com profile page but if you’re having problems you can check out their FAQ for help.

Once you have your API key and the plugin is installed and activated on your own blog you’re almost ready to go. With your API key in hand, go to the “Akismet Configuration” panel available under “Plugins” on the WordPress administration. Now you simply paste your API key into the box provided and save.

Akismet will begin to automatically filter your comments, trackbacks and pingbacks as they come into your blog. Be careful though as Akismet is known to occasionally incorrectly mark valid comments as spam. You’ll have to periodically go through the comment moderation queue to look for any of these false-positives.