Cerb is a fast and flexible Web-based platform for business collaboration and automation. It helps you remember anything about anyone, collaborate from anywhere, deftly reply to a flood of email, automate, stay informed, capture feedback, track time, flag opportunities, manage tasks, share expert knowledge, and otherwise execute efficiently.
MIMP is a version of the popular webmail client IMP intended for mobile phones and PDAs. Basic webmail functionality is implemented, including mailbox viewing and paging, viewing messages, deleting, replying, forwarding, and composing new messages. It utilizes the Horde Application Framework.
Roundcube Webmail is a browser-based, multilingual IMAP client with an application-like user interface. It provides the full functionality you expect from an email client, including MIME support, address book, and folder manipulation. High extensibility is granted by the plugin API and the user interface is fully skinnable using XHTML and CSS 2.
Insight Server is a Linux-based email server utilizing open source components to provide a highly reliable, scalable, and cost effective email solution for customers of all sizes. It's designed to facilitate complete messaging and collaboration capabilities within a company. It supports all standard protocols, and provides backup and recovery tools, server redundancy, migration tools, and resource management.