swedish characters doesn't work

[Rakesh khapra]

I m trying to send a email and sms alert to people and it works fine on all systems expect on Iphone,the problem is swedish charcters doesn't show on iphones used by people in sweden but works absolutely fine on iphones in india.
the code i m using is right below,plz have a look and not into the problem as problem is a bit strange.
$headers = "MIME-Version: 1.0\n" ;
$headers .= "Content-Type: text/plain; charset=\"UTF-8\"\n";
$headers .= "X-Priority: 1 (Highest)\n";
$headers .= "X-MSMail-Priority: High\n";
$headers .= "Importance: High\n";


// Additional headers
$headers .= 'From: Rakesh <[e-mail]>' . "\r\n";
foreach($disemail as $email)
{
$to = $email;
$subject = $succMessage['email_subject'];
$message = $smsText;
mail($to,'=?UTF-8?B?'.base64_encode($subject).'?=',$message,$heade r);
}
}
if (stripos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== FALSE) {
$smsText = utf8_encode($smsText);
}