Gaze is a lightweight Gmail checker that sits in the system tray and notifies you of new messages in your inbox. You can configure how often the program will use the ROME API to check the Atom RSS feed for your inbox, as well as optional combined notifications, custom browser actions, theming, and more.
Engroup is an enterprise groupware system promotes collaboration among members in a team or company. It also helps members manage their business better. It has the following modules: a dashboard that aggregates contents from the mail system and RSS from some known sources; private messages, an alternative method for fast communication among members to replace chatting or email; email, which supports the IMAP protocol with SSL enabled; a forum, implemented with JForum; a wiki, implemented with JSPWiki; HRM to manage employee information; CRM to manage customer information; a document management system; a project management system; a todo list to track private tasks of a user; and an RSS reader.
Mireka is a mail server with SMTP, Mail Submission, and POP3 services. It can also be used as an SMTP proxy. As a proxy, it can help to prevent or diagnose mail problems, like outgoing backscatter spam. It provides detailed logging, basic mail traffic statistics, tarpit to prevent email harvesting, and loop detection. It can filter email by DNSBL, SPF, mail size, local domains, and recipients list. Local recipients can be specified using regular expressions. TLS is supported for incoming connections. Aliases, forward lists, and very simple mailing lists can be configured in XML. Custom filters and other components can be written in Java, and they can be easily implemented and installed.
JWebEngine is an embeddable component that is far more advanced than the internal Sun HTML renderer since it flawlessly passes the Mail Accid and the Accid 1 test. It can easily be used as a JavaHelp or Mail Client renderer in your own applications. Even headless rendering is possible, for thumbnail generation for example. JWebEngine is already being used in the products i-net Crystal-Clear and i-net HelpDesk.
mailxel is a personal mail store and mail client with a focus on the management and organization of high volume mail boxes. The main features are fast search, tagging, GTD inbox management workflow, efficient data storage, address management, automated server-side mail folder organization, and normal mail functionality (send, receive, forward, etc.).
exJello is a JavaMail provider that connects to a Microsoft Exchange server (actually, it uses the WebDAV interface exposed by Outlook Web Access). It is designed as a drop-in replacement for the standard POP3 and SMTP providers. This allows you to send and receive messages through your Exchange server in situations where a POP3/SMTP interface is not available (through a restrictive firewall, for example, or if your administrator simply does not provide a POP3 or SMTP gateway).
DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any email/calendar client (e.g. Thunderbird with Lightning or Apple iCal) with an Exchange server, even from the Internet or behind a firewall through Outlook Web Access. DavMail now includes an LDAP gateway to Exchange global address book and user personal contacts to allow recipient address completion in the mail compose window, and full calendar support with attendees free/busy display.