Anti-Spam SMTP Proxy Server implements multiple spam filters
Anti Spam SMTP Gateway
CIDRAM: Classless Inter-Domain Routing Access Manager.
An easy-to-use anti-spam email gateway
Virtual Appliance of RadicalSpam
A simple PHP-AJAX captcha application
A program that detects and blocks phishing, pharming, Hacker's C&C.
This Plugin provides very simple and powerful captcha for your blog
Análisis forénsico, entorno unificado y extracción de datos
Catch-a spammer with a CAPTCHA.