Domain Technologie Control (DTC) is a Web-based control panel for hosting that can delegate the task of creating subdomains, email, and FTP accounts to users for the domain names they own. It has support for many programs, including bind 8 and 9, MySQL, Apache, PHP 4, qmail, Postfix, Courier, Dovecot, ProFTPD, Webalizer, and mod-log-sql. It can also generate backup scripts, calculation scripts, and config files using a single system UID/GID, and monitor all traffic accounting per user and per service. It is fully skinnable and translated into several languages.
Dovecot is an IMAP server whose major goals are security and extreme reliability. It uses index files to optimally store the mailbox state, which makes it very fast even with huge mailboxes. Indexes won't prevent external mailbox updates, so Dovecot is still fully compatible with standard Maildir and mbox formats. There's also a fully featured POP3 server included.
Elm Millennium Edition is a text-based mail client. There are two branches: Elm 2.4ME+, which is based on Elm 2.4, and Elm ME+ 2.5, which also incorporates some code from Elm 2.5. Elm Millennium Edition contains enhanced MIME and character set support. A subset of UTF-8 (Unicode) is handled. It can read mail from a local mbox and POP and IMAP folders and can pass mail to the PGP or GPG programs. It can also view digests as a mailbox and reassemble fragmented (message/partial) messages. It includes modules for TLS/SSL, iconv, and SMTP.
Elmtree Express Server is a realistic alternative to the Microsoft Windows server plaftorm. Express Server is a workgroup server solution, providing your business with integrated email, print management, and data storage functionality, all in one easy package. It includes an email server, a central address book via LDAP server, a DHCP server, a central file server, a print server, automated daily backups, GUI administration tools, and more.
MailMan is one of the most stable, mature, and robust Web-based email systems available. The overall goal of the system is to provide the simplest possible way to add a Web-based email system to any Web site, so ease of installation and maintenance was the first goal in MailMan's design. It has no dependencies and no known incompatibilities with any Web server or mail server. It supports sending and receiving attachments, a single-frame or multi-frame interface, HTML-formatted messages, user options, address books, mail folders, and more.
Eremove is a small GTK-based application with a simple interface. It allows you to view a summary of the contents of a mailbox on a POP3 server. It displays a list with size, atachment, from, date, and subject. It allows you to preview the headers/contents of each email, and select some or all of the messages for deletion.
FreePOPs is a POP3 server that is scriptable in LUA. This means that you can tailor it to your needs by writing a plugin. Plugins are currently implemented for using FreePOPs as an RSS aggregator, a POP3 forwarding server, and a POP3 interface to the webmail services of libero.it, inwind.it, iol.it, blu.it, lycos.it, tin.it, virgilio.it, gmail.com, aol, hotmail, fastmail, mail2world, yahoo and many more (see the Web site for an exaustive list).
GROUP-E is collaboration software which integrates groupware, project management, and business server on one platform. The solution is based on a LAMP architecture (Linux, Apache, MySQL, PHP). GROUP-E offers project management, transparent Samba (file server) integration, integration of Cyrus IMAP server with administration and personal SIEVE filters, support for SyncML 1.0, LDAP-based user management with single sign-on authentication, and LDAP contact databases. GROUP-E also provides ActiveSync for synchronization.