Sunのページをまねてみたのですが、これでも駄目でした。。。

<%@ page language="java" contentType="text/html; charset=UTF8"%>
<%@ page pageEncoding="UTF-8"%>
<%@ page import="java.util.*, javax.mail.*, javax.mail.internet.*" %>
<%
Properties props = new Properties();
Authenticator auth = new MyAuthenticator();
Session session = Session.getDefaultInstance(props, auth);
MimeMessage message = new MimeMessage(session);
String sname = (String)session.getValue( "sName" );
String gname = (String)session.getValue( "gName" );
String comments = (String)session.getValue( "Comments" );
String semail = (String)session.getValue( "sEmail" );
String gemail = (String)session.getValue( "gEmail" );
InternetAddress from = new InternetAddress(semail);
message.setFrom(from);
InternetAddress to1 = new InternetAddress(gemail);
InternetAddress to2 = new InternetAddress(semail);
message.addRecipient(Message.RecipientType.TO, to1);
message.addRecipient(Message.RecipientType.TO, to2);
message.setSubject( "Test mail","ISO-2022-JP");
message.setText("Test","ISO-2022-JP");
message.saveChanges(); // implicit with send()
Transport transport = session.getTransport("smtp");
transport.connect("smtpout.xxxxx.net", "accountxxxxx", "passxxxx");
transport.sendMessage(message, message.getAllRecipients());
transport.close();
response.sendRedirect("/ConfMail2.jsp");
%>