I get spam messages through my contact forms. How can I stop them?

You can protect your contact forms with the anti-spam features that Contact Form 7 provides.

Contact Form 7 supports spam-filtering with Akismet. Intelligent reCAPTCHA blocks annoying spambots. Plus, by using the disallowed list, you can block messages containing specific keywords or those sent from specified IP addresses.

Just another contact form plugin for WordPress. Simple but flexible.