I'm running an app under Eclipse 3.0.2 and getting the following
runtime error:
java.lang.NoClassDefFoundError: javax/mail/Session

with the following line of code:
session = Session.getDefaultInstance(props, null);

The app compiles without a problem.

The apps' classpath follows:
<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    <classpathentry kind="src" path=""/>
    <classpathentry exported="true" kind="lib" path="/src/bin"/>
    <classpathentry exported="true" kind="con"
path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
    <classpathentry exported="true" kind="lib"
path="/lib/activation.jar"/>
    <classpathentry exported="true" kind="lib" path="/lib/servlet.jar"/>
    <classpathentry exported="true" kind="lib" path="/lib/mail.jar"/>
    <classpathentry kind="output" path="bin"/>
</classpath>

The jar files necessary for the app and another accompanying app are in
project called 'lib'.
The lib project is is included in the Java Build Path for this project,
though I don't think
that is relevant.

Where else would Eclipse be looking for the mail.jar during runtime?
I've also added the location of the jar files to my system classpath
but the error still occurs.

Thanks!