Overview
WordPress anti-spam plugins filter out unwanted comment spam, one of the top causes of high CPU usage on an overloaded blog. Check the "Comments" section of your WordPress install to see if you're being spammed — if the comments look like the spam mail in your inbox, installing an anti-spam plugin helps stop the incoming flow of spam.
Anti-spam plugins
There are a lot of anti-spam plugins that are available for WordPress. For example:
- Pros: Spam checking happens off server, low impact on server overhead, works with most feedback forms.
- Cons: Needs an API Key in order to run.
Using a combination of plugins is recommended, but keep in mind that the CAPTCHAs plugin is not always user friendly.