Kolab is a groupware system that provides a comprehensive and flexible solution for workgroups. Email, contacts, and group calendars can be managed via the Web, Windows/Outlook, and Linux/KDE. It supports offline synchronization and full seamless support of mixed client environments because the Kolab-XML storage format is fully open and avoids MAPI/TNEF.
AfterLogic WebMail Lite PHP is a Webmail script with a modern AJAX interface. It supports IMAP accounts, SMTP, and SSL (including Gmail). Users can check and send mail and use an address book. It provides a slick skin, a three-pane view, non-English language support, UTF-8 support, IMAP folders, and viewing and composing HTML mail. A MySQL backend is supported, with Web-based administration and installation and cPanel/Plesk/DirectAdmin integration.