Zimbra - Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.
Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Roundcube - Web-based IMAP email client
Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
hMail Server - hMailServer is a free e-mail server for Microsoft Windows.
Lightning Calendar - Organize your life — it’s about time!