email problem

[eluser]C_Line[/eluser]
i send email to yahoo and the link can be click
but when i send to hotmail, the link unclickable

heres my code

Code:

$message =
"Untuk mengaktifikasikan account anda pada Sinar Jaya Online, klik link dibawah ini
{unwrap}".base_url()."index.php/main/aktivasi_account/".$regis_id."{/unwrap}";


my config
$config = array(
    'protocol' => 'smtp',
    'smtp_host' => 'ssl://smtp.mail.yahoo.com',
    'smtp_port' => 465,
'smtp_timeout' => 10,
    'smtp_crypto' => 'ssl',
"smtp_user" => "[email protected]",  
"smtp_pass" => "xxx",
    'mailtype'  => 'text',
'charset'   => 'utf-8',
'newline' => "\r\n"
);  
$this->email->initialize($config);

thx for help