Java EE (Java Enterprise Edition) General Discussion

I'm getting a host of exceptions from my bounce mail processor.

Does anyone have any link or book recommendations where I can find out more about this? Or suggestions?

14:58:01,130 ERROR [BouncedMailJob] Unknown encoding type: null
java.io.UnsupportedEncodingException: KOI8-U
        at sun.io.Converters.getConverterClass(Converters.java:218)
        at sun.io.Converters.newConverter(Converters.java:251)
        at sun.io.ByteToCharConverter.getConverter(ByteToCharConverter.java:68)
        at sun.nio.cs.StreamDecoder$ConverterSD.<init>(StreamDecoder.java:224)
        at sun.nio.cs.StreamDecoder$ConverterSD.<init>(StreamDecoder.java:210)
        at sun.nio.cs.StreamDecoder.forInputStreamReader(StreamDecoder.java:77)
        at java.io.InputStreamReader.<init>(InputStreamReader.java:83)
        at com.sun.mail.handlers.text_plain.getContent(text_plain.java:64)
        at javax.activation.DataSourceDataContentHandler.getContent(DataHandler.java:745)
        at javax.activation.DataHandler.getContent(DataHandler.java:501)
        at javax.mail.internet.MimeMessage.getContent(MimeMessage.java:1342)
        at com.imc.quartz.jobs.BouncedMailJob.dumpPart(BouncedMailJob.java:540)
        at com.imc.quartz.jobs.BouncedMailJob.execute(BouncedMailJob.java:260)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:195)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520)

Thanks!