这样可以解决,试试吧::
BodyPart bp = new MimeBodyPart();
int indexof =filename.lastIndexOf("/");
String fileNameNew=MimeUtility.encodeText(filename.substring(indexof),"utf-8",null);
DataSource dataSourse=new FileDataSource(filename);
bp.setDataHandler(new DataHandler(dataSourse));
bp.setFileName(fileNameNew);
mp.addBodyPart(bp);
把你的环境的编码修改成UTF-8试试~~