SpamAssassin - Use this program to "Unspam" your mailbox(es).
ModSecurity - ModSecurity is an Open Source web application firewall developed by Trustwave's SpiderLabs.
Oikik Antispam - Oikik is a cloud-based email filtering service that works with your existing email service.
Cloudflare WAF - Whether you want automatic WAF protection from known vulnerabilities or have custom WAF rules, our real-time platform can do it.
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
Naxsi - NAXSI means Nginx Anti XSS & SQL Injection.