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.
Bulk Mailer helps speed the delivery of an email message to many recipients using Sendmail. It's best used in parallel with a mailing list manager such as Majordomo. For input, it takes a file of recipient addresses (one address per line) and a message (with headers already attached) to be sent to the recipients. It sorts the recipient list by reversed domain (so similar ones sort together), splits up the recipients into several groups containing no more than N domains each, creates an SMTP envelope for each group of recipients, and feeds each envelope to sendmail.
Citadel is an advanced messaging and collaboration system for groupware and BBS applications. Users can connect to Citadel using any telnet, WWW, or client software. Among the features supported are public and private message bases (rooms), electronic mail, real-time chat, paging, shared calendaring, address books, mailing lists, and more. Unlike other collaboration servers, Citadel provides its own data stores and is therefore extremely easy to install; you don't have to "bring your own" email and database because they're built in. The server is multithreaded and scalable. In addition, SMTP, IMAP, and POP3 servers are built-in for easy connection to Internet mail. Citadel is both robust and mature; it has been in production since 1987.
CMC is a Perl/GTK+ mail client designed to be easy to use and fill the needs for features that are not present in other mailers, including HTML mail, multiple accounts, support for external viewers, compatibility with other mail clients, easy extendability, multiple mailboxes, etc.
CommuniGate Pro is a high-end, industry strength Internet Mail server. It supports over 24 different operating systems including Linux/LinuxPPC,Solaris, MacOS X, FreeBSD, WindowsNT, BSDi, AIX, AS/400, HP/UX, Tru64, BeOS, IRIX, and S/390 for Linux. The CommuniGate Pro server takes full advantage of modern multi-threaded and multi-processor environments, and includes anti-spam protection, administration via the web, extensive multi-domain support, dial-up capabilities, cluster support, and unique IMAP multi-mailbox features. As a commercial product, it is distributed as keyware. The Free trial version is not time- or feature- limited.
The Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols such as ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. Courier provides ESMTP, IMAP, POP3, Webmail, and mailing list services within a single consistent framework. Individual components can be enabled or disabled at will. Courier implements basic Web-based calendaring and scheduling services integrated in the Webmail module.