java.lang.ClassNotFoundException when using groovy in place of jelly

[Jason Swager]

Quick background: I'm trying to fork the email-ext plugin.  Not to make another email notification plugin, to make notifications to a different form of collaboration service.  I figured email-ext would be the best place to start, with all its features and such.  Things were going well, until...

To the system config.groovy, I added a validation button to test the system wide settings.  The groovy calls into the plugin to execute validation, the Java validation code creates a class from a JAR that I added via the proper Maven dependencies.  But I get a "java.lang.ClassNotFoundException: com.mystuff.MyClass"

Is there someplace I'm supposed to specify my additional JARs, beyond the pom.xml file?

Any help greatly appreciated,

Jason