GreenMail is a suite of email servers for testing purposes and sandbox development. It supports SMTP, POP3, and IMAP (including SSL) and can be embedded into any Java application or unit test. The GreenMail Service (SAR) extension runs as a JBoss embedded developer mail server sandbox, manageable via JMX.
JCatapult is a development platform written in Java. Built for modularization, JCatapult allows developers to build modules such as a blog, content-management system, wiki, or any other reusable set of features and use them across multiple applications. Built on top of open source technologies, JCatapult is a robust and scalable platform. However, it is also agile and lightweight because it uses a convention over configuration approach.