AUC (Authenticated User Community) is an intranet system designed for use in an educational organization but is also useful in many other settings. It offers the ability for users to have a uniform web-based interface to discussion forums, e-mail (similar to hotmail, etc.), file management, and a searchable user database. Also, "Interactive Classrooms" provide a means for students and teachers to have a web-based extension to their in-class interaction. The system runs from a C-based monolithic CGI script. MySQL is used for database storage. Also, the web-based mail client supports MIME parts/attachments, IMAP, mbox, and multiple mail folders.
BrowserExpress is a Web-based e-mail client. BrowserExpress provides a Web browser interface to any mail server, giving all your users Web-based e-mail from any Web browser. The BrowserExpress interface is fully customizable to support your branding, banner advertisements, and language choice. BrowserExpress implements POP3, SMTP, LDAP, and MIME standards.
NOCC is a simple and fast Web-based e-mail reader which can handle POP3, SMTP, and IMAP servers. It is written with PHP5, and uses sessions, has low requirements (no database, frames), and is easy to install. It also features multi-language support, MIME attachment decoding/encoding, and the ability to display HTML messages.
NS WebMail offers standard mail functions for POP3 inbox management. Mail is sent using SMTP protocol. It has been designed to be light and simple, to avoid having to use heavy IMAP or SQL servers, and it has full MIME support for incoming and outgoing mail. It is Perl-strict and mod_perl-compliant, and has security using HTTP authentication or cookies. LDAP connectors are also available (as optional plug-ins) for authentication and read-only address book. Two interfaces are available (with and without frames). It is able to recognize tags from spam detection software (Spamassassin is supported out of the box).
oMail-webmail is a Webmail solution for mail servers based on qmail and optionally vmailmgr or vpopmail. The mail is read directly from maildirs on the hard disk, which is much quicker than using protocols like POP3 or IMAP. Other features includes multiple language support (English, French, German, Japanese, Chinese, and many more), HTML and pictures inline display, folders, and address book support.
SquirrelMail is a standards-based Webmail package. It includes built-in pure PHP support for the IMAP and SMTP protocols, and all pages are rendered in pure HTML 4.0 for maximum compatibility across browsers. It has very few requirements, and is very easy to configure and install. It has all the functionality you would want from an email client, including strong MIME support, address books, and folder manipulation.
WebCit is a Web-based, AJAX-enabled frontend to the Citadel groupware/collaboration system. It is an attractive Web middleware layer that allows user-friendly access. By combining WebCit and Citadel, you can have a versatile online environment with many users concurrently accessing the same system using the user interface of their choice (text, Web, or downloaded client software).
NullLogic Groupware is a modular Web-based groupware and email system designed for contact management and event scheduling. Additional features include private messaging, public discussion forums, webmail, shared bookmarks, file sharing, call tracking, order processing, an XML-RPC API, and integrated POP3 and SMTP servers.