این رو به
if (function_exists('mb_encode_mimeheader')) {
$subject = mb_encode_mimeheader($subject, "utf8_general_ci", "B", "\n");
}
else {
// you need to enable mb_encode_mimeheader or risk
// getting emails that are not UTF-8 encoded
}
$headers .= "MIME-Version: 1.0\n";
$headers .=...