This is a subclass of javax.mail.Reference and an ObjectFactory for javax.mail.Session objects.
The subclassing of Reference allows all of the setup for a javax.mail.Session
to be captured without necessitating first instantiating a Session object. The
reference is bound into JNDI and it is only when the reference is looked up that
this object factory will create an instance of javax.mail.Session using the
information captured in the Reference.