To use the Java API, you need to load the ENS plug-in. For instructions on loading the ENS plug-in, see Appendix C in the Messaging Server Administration Guide. By default, ENS is already enabled.
In addition, you need to install the following software, which is not provided with either Messaging Server or Calendar Server:
Java Development Kit (JDK) 1.2 or later
Java Message Service 1.0.2a or later (tested with 1.0.2a)
You can download this software from:
http://java.sun.com.