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.
Lubuntu - Lubuntu is a fast and lightweight operating system with a clean and easy-to-use user interface. The core of the system is based on Linux and Ubuntu. Lubuntu uses the minimal desktop LXDE, and a selection of light applications.
iRedMail - A fully fledged, free email server solution, an open source project (GPL v2).
Xubuntu - Xubuntu – Xubuntu is an elegant and easy-to-use operating system. Download XubuntuXubuntu – Xubuntu is an elegant and easy-to-use operating system. Feature Tour.
mailcow - An open source mailserver suite.
Ubuntu - Ubuntu is a Debian Linux-based open source operating system for desktop computers.