I think the error message is quite obvious.
java.lang.NoClassDefFoundError: com/sun/activation/registries/LogSupport
You're missing activation.jar or you're using old/wrong version which does not contain LogSupport class.
You mentioned that this is a test class. Do mean by "test class" a unit test class or just a "test" class? In unit tests it's not recommended that the unit tests have dependencies to external resources like smtp server etc.... this is just a side note
if a trainstation is where the train stops, what's a workstation...