Proxmox Mail Gateway - Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.
pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
Zentyal - Linux directory, domain, mail, gateway and infrastructure server for SMBs.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...