docNCRYPT - docNCRYPT is a cybersecurity platform which only focuses on its core services in protecting your email directly from the different email service provider and allows you to integrate your business email portal in the online service.
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.
Websense Email Security - Websense Email Security is a powerful email protection tool that helps you strengthen the security of your network.
HEY - Email at its best, new from Basecamp.
Cisco Email Security - Cisco Email Security protects against ransomware, business email compromise, spoofing, and phishing.
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.