BCC: header not working.

[denoteone]

My mail function is working but the BCC's in the header are not. Am I missing something. below are my headers.

 

$to = $_POST['email_address'];

$subject = 'Thank You for requesting info about STRATACACHE';

$random_hash = md5(date('r', time()));

$headers = "From: [email protected]\r\nReply-To: [email protected]\r\n";

$headers .= "Content-Type: multipart/mixed; boundary=\"PHP-mixed-".$random_hash."\"\r\n";

$headers .= "BCC: [email protected],[email protected]\r\n";

$attachment = chunk_split(base64_encode(file_get_contents('pdfs/'. $_POST['file'] .'')));