Mail pdf attachment gets file corrupted

[narenmedoju]

I'm facing problem with mail pdf attachment gets file corrupted. When we click on the attachment "Adobe reader could not open xx.pdf because it is either not a supported file type or because the file has been damaged(for example, it was send as an email attachment and wasn't correctly decoded)" error message is showing. Below is my email attachment code.

$companyinfo = "xxxx";
     $ccinfoges = "test";
     $message = "test message";
    include("test/mpdf/mpdf.php");
            $mpdf=new mPDF();   
            $mpdf->ignore_invalid_utf8 = true;
            $stylesheet = file_get_contents('appstyle_pdf.css');
 
            $mpdf->WriteHTML($stylesheet,1);
            $mpdf->WriteHTML($output);
 
 
            $comname = preg_replace("/[^A-Za-z0-9]/","",$_POST['company']);  
 
            $name = $dirname.str_replace(" ","-",$comname)."_".$time_stamp.".pdf";        
            $mpdf->Output($name,"F"); 
            $file = $name;
            $crlf = "\n";
 
            $filename = basename($file);
            $file_size = filesize($file);
            $content = chunk_split(base64_encode(file_get_contents($file))); 
            $uid = md5(uniqid(time()));
 
            $headers = "\r\n"
                  ."MIME-Version: 1.0\r\n"
                  ."Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n\r\n"
                  ."This is a multi-part message in MIME format.\r\n" 
                  ."--".$uid."\r\n"
                  ."Content-type:text/plain; charset=iso-8859-1\r\n"
                  ."Content-Transfer-Encoding: 7bit\r\n\r\n"
                  .$message." 
                  ".$companyinfo." 
                  ".$ccinfoges."\r\n\r\n"
                  ."--".$uid."\r\n"
                  ."Content-Type: application/octet-stream; name=\"".$filename."\"\r\n"
                  ."Content-Transfer-Encoding: base64\r\n"
                  ."Content-Disposition: attachment; filename=\"".$filename."\"\r\n\r\n"
                  .$content."\r\n\r\n"
                  ."--".$uid."--";
        mail($testmail, $subject, "$message \f $companyinfo $ccinfoges", $headers);

when sending the attachment to Gmail it's working fine some of the domains pdf file is corrupted.We are using windows server. What could possibly be happening? Any help ?