com.sun.mail.util
Classes 
ASCIIUtility
BASE64DecoderStream
BASE64EncoderStream
BEncoderStream
CRLFOutputStream
LineInputStream
LineOutputStream
MailSSLSocketFactory
PropUtil
QDecoderStream
QEncoderStream
QPDecoderStream
QPEncoderStream
SocketFetcher
TraceInputStream
TraceOutputStream
UUDecoderStream
UUEncoderStream
Exceptions 
DecodingException
FolderClosedIOException
MessageRemovedIOException