phpmailer 发送邮件乱码问题

Zend_Loader::loadFile('tools/Class.phpmailer.php');
$mail = new PHPMailer();
$mail->CharSet = "utf-8";//设置编码方式
$mail->Encoding = "base64";
$mail->IsSMTP();// 启用SMTP
$mail->Host = MAIL_HOST; //SMTP服务器
$mail->SMTPAuth = true;                  //开启SMTP认证
$mail->Port = 25;
$mail->Username = SMTP_NAME;            // SMTP用户名
$mail->Password = SMTP_PWD;                // SMTP密码
$mail->From = SMTP_NAME;            //发件人地址
$mail->FromName = "tourxper.com";              //发件人
$mail->AddAddress($tomail, $tomailname); //添加收件人
$mail->AddReplyTo(SMTP_NAME);    //回复地址
$mail->IsHTML($isHtml);                 // 是否HTML格式邮件
$mail->Subject = $Subject;          //邮件主题
$mail->Body    = $Body;        //邮件内容