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.
phlyMail is a groupware, webmailer, and PIM. It offers unlimited nested groups, unlimited POP3/IMAP profiles, quotas, an integrated address book, a calendar with multiple reminders and event repetitions, a file manager with an integrated WebDAV server, the ability to send faxes, SMS support (which lets you send SMS, get reminded of events via SMS, and get email notification via SMS), a bookmark manager, themes, and multilingual support. It uses either sendmail or SMTP to send email, and can handle MIME and SSL connections. Support for IDN (Internationalized Domain Names) is included. Through its modular design, it's easy to add completely new features as modules, which can be plugged into the system.
Usermin For Webmail is a modified version of the Usermin package that is pre-configured for use as a Web-based email client. It is designed to work on systems running a local IMAP server, such as Dovecot. By default, users can read email, setup autoresponders and forwarding with Procmail, filter mail with simple rules, change their passwords, and manage folders.
IMAP Folder Manager was created to manage IMAP folders for large user bases. It can list, create, delete, and rename folders, count messages in a folder, move or copy all the messages from one folder to another, and empty a folder. It supports PROXYAUTH for easy user management and has a simple but powerful argument interface, able to do things like "create folder2, move messages from folder1 to folder2, and delete folder1" in a single compact line.
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.
IndiMail is a messaging platform built using qmail and other messaging software. IndiMail has the ability to distribute the users in a domain across multiple hosts. IndiMail has multiple queues (called a queue collection), which can achiever very high concurrencies. The system IDs and configuration files used by IndiMail are all configurable through a set of environment variables, allowing you to customize IndiMail the way you want. IndiMail does not use hard-coded uid/gid in the executables, which makes it easy to distribute a binary package. IndiMail has features that any modern email server should have: SMTP, QMQP, QMTP, IMAP, POP3, DKIM, BATV, greylisting, filtering capability, and spam/virus control.
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.
BEJY is a modular server application. It is packaged, by default, as a Web application container and mail server with SSL. It has functionality similar to inetd, and has some helper classes/functions to ease the implementation of new protocols. It provides a generic multithreaded TPC/IP server implementation with optional SSL support, covering the complete connection and thread management. Each supported service provides its protocol implementation. The current version comes with HTTP, SMTP, POP3, and IMAP protocol implementations. The HTTP protocol implementation also contains a servlet engine, a JSP 1.2 engine, a handler to invoke CGI, and other useful things. The mail protocols require a database using JDBC, as MySQL, MSSQL, and others.
getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
imapbiff is a small perl/tk program that notifies you of new mail in an IMAP mail account. It only checks IMAP accounts, not local mail files or POP accounts. When you do not have any unread messages in your IMAP Inbox, it will display a mailbox icon with the flag lowered. When it detects new messages in your IMAP Inbox, it will beep and raise the flag. Whenever it is querying the IMAP server, a "?" is displayed to indicate that it is checking for messages.