Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
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.
Cypht - All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail.
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.
Mailpile - Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
Cisco Email Security - Cisco Email Security protects against ransomware, business email compromise, spoofing, and phishing.