Some web hosts do not allow for plugins such as Akismet to function properly. This is because they turn off the PHP function fsockopen for security reasons. When they do this, any plugin that connects to an outside source doesn’t function correctly. The biggest issue then is the inflow of spam.
I’ve found two plugins that seem to help take control of spam comments and trackbacks when Akismet isn’t available. Neither are perfect, but together they make a world of difference in the fight against spam.
The first is Cookies for Comments. This plugin places a cookie into the visitors browser when they arrive at your site. Once they leave a comment, the plugin checks to see if that cookie exists. If there is no cookie, then it’s marked as spam. From my testing, it works quite well.
The second is Simple Trackback Validation. This plugin checks the site that is supposedly leaving the trackback and ensures that the IP is good and that the site is actually linking to yours.
The downside to both plugins is that they either pull all questionable comments & trackbacks into moderation or they delete them. This means that you’ll continue to get flooded with moderation requests or they’ll just be deleted and, if something is marked spam accidentally, you’ll never know.
Both plugins work well and have done a great job at protecting a blog when Akismet is not an option.
The good news for Akismet fans here is that there is news that in WordPress 2.7, Akismet may work without the fsockopen function via a HTTP API. This would then allow for Akismet, and other pluigns, to work on additional hosting platforms where it currently cannot properly function. Lets hope it works as good as it sounds.
For now, Cookies for Comments and Simple Trackback Validation are two great solutions to minimizing the flow of spam on hosting situations where Akismet is not available, or for those that choose not to use Akismet.