PHP Encryption openssl_pkcs7_encrypt() Failing

$fp = fopen($unenc_path, "w");
 fwrite($fp, $msg);
 fclose($fp);

 $easy_access_emails = 'person@##.com';
 $headers =   "From: support@##.com <support@##.com>n" .
              "Reply-to: support@##.comn" .
              "Subject: " . $subject . "n";

 $key = implode("", file("../newcert.pem"));

 $ArrayMessageProperties = explode("n", $headers);

 $unenc_path = '..\tmp\'. preg_replace('/[^0-9]/','', microtime()) . rand(0,1000) . "msg.txt";
 $enc_path = '..\tmp\'. preg_replace('/[^0-9]/','', microtime()) . rand(0,1000) . "enc.txt";

 if (openssl_pkcs7_encrypt($unenc_path, $enc_path, $key, $ArrayMessageProperties))
 {
    $info = file_get_contents($enc_path);

    foreach ($easy_access_emails as $email)
    {
         mail($email, $subject, $info, $headers);
    }
} else {
    die("Failed Encryption");
}

w3wp.exe:4172  C:windowssystem32tmp4277530010012336..msg.txt    PATH NOT FOUND  Options: Open Access: Read