One of the few options to try and combat SPAM on your zencart install, is to try and implement a CAPTCHA text/image on your contact us page. I recently updated a contribution I created several months ago. This reCAPTCHA contribution will add configuration fields to the database for your api key and password, color theme selection, and enable/disable feature on contact us form. The original contribution had used native mysql queries, so I have updated the contribution to support zencart’s $db:Factory object.Download the file below, and read the included instructions. There is only one original core file that has been overwritten. The reCAPTCHA logic had to be added to the contact us form validation.
Update 10/10/2010: This contribution has been updated to use Zencart 1.3.9g, and has added reCAPTCHA to several other pages. Please checkout download link at bottom of page.
Upload files to your zencart installation folder, and login into your admin page. The contribution will automatically install it’s configuration values. On a page refresh, you should see a new box under Admin->Configuration->reCAPTCHA.
If you are upgrading from a previous install of this mod, append [&remove_recaptcha=yes] to the url in your admin page, and press [Enter]. This will reinstall the contribution.