帮帮忙！现在要实现邮件发送（还必须要匿名发送）！
这是我写的代码：我用的是smtp.163.com   是不是163必须要经过验证用户名和密码的。我们经理看了说   最好用匿名发送（和我们做的东西有关）。高手帮我看下怎么解决！我也找了半天的资料，没实现！


public   class   SendMail   {

public   SendMail   ()   {

}
private   static   String   PROTOCOL   =   "smtp ";

private   static   String   KEY_MAIL_SMTP_HOST   =   "mail.smtp.host ";

private   static   String   KEY_MAIL_SMTP_PORT   =   "mail.smtp.port ";

private   static   String   KEY_MAIL_SMTP_AUTH   =   "mail.smtp.auth ";


public   static     boolean   send(String   to   ,   String   from   ,   String   subject,   String   body,   String   affixFilename)   {
String   host   =   SystemConst.SMTP_HOST;//设置邮件服务器
String   account   =   SystemConst.SMTP_USERNAME;//自己配置调用的用户名（默认的是我的）
String   pwd   =   SystemConst.SMTP_PASSWORD;//密码
boolean   br   =   false;
Session   session;
Properties   props   =   System.getProperties();
props.put(KEY_MAIL_SMTP_HOST,   host);
props.put(KEY_MAIL_SMTP_AUTH,   "true ");

MailAuthenticator   ma   =   new   MailAuthenticator   (account,   pwd);
session   =   Session.getInstance(props,   null);
session.setDebug(true);
Message   msg   =   new   MimeMessage(session);
try   {
msg.setFrom(new   InternetAddress(from));
msg.setRecipients(Message.RecipientType.TO,   InternetAddress.parse(
to,   false));
msg.setSubject(subject);
boolean   blnAffixExist   =   false;
if   (affixFilename   ==   null   ||   affixFilename.trim().length()   ==   0)   {
blnAffixExist   =   false;
}   else   {
File   file   =   new   File(affixFilename);
if   (file.exists())   {
blnAffixExist   =   true;
}
}
if   (blnAffixExist   ==   false)   {
msg.setText(body);
}   else   {
Multipart   mp   =   new   MimeMultipart();
BodyPart   bp   =   new   MimeBodyPart();
FileDataSource   fileds   =   new   FileDataSource(affixFilename);
bp.setDataHandler(new   DataHandler(fileds));
bp.setFileName(fileds.getName());
mp.addBodyPart(bp);
BodyPart   bp2   =   new   MimeBodyPart();
bp2.setContent(
" <meta   http-equiv=Content-Type   content=text/html;   charset=gb2312> "
+   body,   "text/html;charset=GB2312 ");
mp.addBodyPart(bp2);
msg.setContent(mp);
}

msg.setSentDate(new   Date());
Transport   transport   =   session.getTransport(PROTOCOL);
transport.connect((String)   props.get(host),account,   pwd);
transport.sendMessage(msg,   msg.getAllRecipients());
//Transport.send(msg);
transport.close();
br   =   true;
}   catch   (Exception   ex)   {
ex.printStackTrace();
}
return   br;
}
}


现在就是向不用通过验证用户名和密码（等于就是匿名