title: Why mail attachment in php send encoded contents instead of PDF file
body: <p>Hello Recently i working on php mail attachment but i faced a problem when i send my attachment to somebody email it will show like </p>
  
  <pre><code>            This is my first mail.Content-Type: application/octet-stream; name="PankajChandwani.pdf"
          Content-Transfer-Encoding: base64
          Content-Disposition: attachment; filename="PankajChandwani.pdf"
  
          JVBERi0xLjQKJaqrrK0KNCAwIG9iago8PAovQ3JlYXRvciAoQXBhY2hlIEZPUCBWZXJzaW9uIDEu
          MSkKL1Byb2R1Y2VyIChBcGFjaGUgRk9QIFZlcnNpb24gMS4xKQovQ3JlYXRpb25EYXRlIChEOjIw
          MTYwNjIzMDY0OTM3WikKPj4KZW5kb2JqCjUgMCBvYmoKPDwKICAvTiAzCiAgL0xlbmd0aCAxMSAw
          IFIKICAvRmlsdGVyIC9GbGF0ZURlY29kZQo+PgpzdHJlYW0KeJydlndYU+cex99zTvZgJCFsCHuG
          pUAAkRGmgAzZohCSAAESICQM90BUsKKoyFIEKYpYsFqG1IkoDori3g1SBJRarOLC0USep/X29t7b
          2+8f53ye3/v7vef9jfd5DgCkgEyuMBdWAUAokogj/L0ZsXHxDOwAgAEeYIA9ABxubrZXWFgwkCvQ
          l83IlTuBf9GrmwBSvK8xFXuB/0+q3GyxBAAoTM6zePxcrpyL5JyZL8lW2CflTEvOUDCMUrBYfkA5
          ayg4dYatP/vMsKeCeUIRT86Rcs7mCXkK7pXzhjwpX86IIpfiPAE/X87X5WycKRUK5PxGESvkc+Q5
  </code></pre>
  
  <p>encoded contents this is my mail attachment code in php</p>
  
  <pre><code>$path = get_home_path();
  $filename='Pankaj.pdf'; 
   $file = $path.'wp-admin'.'/'.$filename;
   //print_r($file);
      $file_size = filesize($file);
      $handle = fopen($file, "r");
      $content = fread($handle, $file_size);
      fclose($handle);
      $content = chunk_split(base64_encode($content));
  $to = $_REQUEST['email'];
  $subject = 'Test email'; 
  $message = "Hello World!\n\nThis is my first mail."; 
   $message .= "Content-Type: application/octet-stream; name=\"".$filename."\"\r\n";
      $message .= "Content-Transfer-Encoding: base64\r\n";
      $message .= "Content-Disposition: attachment; filename=\"".$filename."\"\r\n\r\n";
      $message .= $content."\r\n\r\n";
  $headers = "From: ankits8@gmail.com\r\nReply-To: ankits8@gmail.com";
  $mail_sent = @mail( $to, $subject, $message, $headers );
  echo $mail_sent ? "Mail sent" : "Mail failed"; die;
  </code></pre>
  
  <p>i can not estimate where i wrong please find out error and help thanks.</p>