phpmailer发HTML邮件超链接点击无效解决办法

phpmailer发HTML邮件超链接点击无效
用phpmailer发送HTML邮件，，

include_once("class.phpmailer.php");;
$formmail="381266902@qq.com";
$subject = "实验";  
$smtp="smtp.126.com";
$username="XXXXXXXX@126.com";
$password="**********";


$mail=new PHPMailer();
$mail->SMTPAuth = true;
$mail->Host=$smtp;
$mail->IsSMTP();
$mail->SMTPAuth=true;
$mail->Username=$username;
$mail->Password=$password;
$mail->From="sou_ba@126.com";
$mail->FromName="Souba激活";
$mail->Sender="sou_ba@126.com";
$mail->Subject =$subject;
$mail->IsHTML(true);
$mail->Body ="google";

$mail->AddAddress($formmail);
if(!$mail->Send())
{
echo "发送失败";
}
else
{
echo "发送成功";
}
?>


可以发送成功的，，

不过进邮箱打开邮件，，点击超链接无效，，、


求高手帮忙解决一下，，，谢谢

------解决方案--------------------
地址前加上HTTP://