Columba is an email client written in Java, featuring a user-friendly graphical interface with wizards and internalionalization support. Its a powerful mail management tool with features to enhance your productivity and communication.
Mailster is a project aimed at testing software mail capabilities. It provides a mail server container to test emails sent by your apps without rewriting your application code.
Galaxy is a free play by email interstellar wargame for multiple players. The object of the game is to conquer the galaxy by colonizing and developing uninhabited planets and attacking neighboring races.
Multiplatform Java 6 application which queries Zimbra server and notifies about incoming events (new mail, appointments etc.) in tray area. Something like (but more than) Zimbra Toaster.
A webmail-client (POP3, IMAP, SMTP) written in Java as a webapp. Very easy to install - just throw the WAR-file into the deployment-directory of your Servlet-container (tomcat, jetty, weblogic, ..) and you're ready! Test ride on the yawebmail-Homepage!
Helper is an integrated PIM and social networking (blog, RSS, foaf, etc) client. Allows to store, annotate and navigate information uniformly by means of folders, tags and categories. Based on OWL, Eclipse RCP and open standards (Dublin Core, foaf, etc).
A multilingual customer relationship management (CRM) system for media organizations that features powerful modules for sales automation, customer service, incoming and outgoing email, template-based HTML newsletters, and a WYSIWYG editor.
Special email client that works with multiple accounts. Main function - check for number of emails changed from last time, and delete selected emails. Using JavaMail for operation. Requires Java 6 to run.