pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
Barracuda Email Security Gateway - Barracuda's Email Security Gateway is a powerful antivirus filter specifically designed to identify and eliminate email-borne threats, stopping hazards before they reach the network.
Zentyal - Linux directory, domain, mail, gateway and infrastructure server for SMBs.
Proofpoint Email Security and Protection - Learn about Proofpoint's email security solutions that protect organizations against threats such as email fraud, phishing, spam, bulk email, and viruses.
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...
Cisco Email Security - Cisco Email Security protects against ransomware, business email compromise, spoofing, and phishing.