Window.Open in chrome opens both popus and new tab - php

Question

I have a strange problem in chrome, I am using window.open to open a new tab and create a pdf using tcpdf and then send it as attachment to a specific address, now in chrome what happens is that it sends 2 mails. If popup is enabled then I get 2 window actions 1. Popup and 2. New Tab, firstly I don't understand how is that possible, I have never seen this.
Then If is disable the popup, it only opens in new tab, but still 2 mails.
Code used to call the popup page and email code is mentioned below. Please help.
window.open('/loancal/rhexportemail.php' + qstring,"_blank");
//Code used to open popup
//------------- EMAIL CODE ----------------//
$to = "someone#gamil.com";
$from = "info#mydomain.com";
$subject = "Loan Enquiry Calculation Cashback - " . $client;
$message = "Please find attached Loan Enquiry Calculation Cashback statement for ".$client."." ;
//a random hash will be necessary to send mixed content
$separator = md5(time());
// carriage return type (we use a PHP end of line constant)
$eol = PHP_EOL;
// attachment name
$filename = $subject.".pdf";
// encode data (puts attachment in proper format)
$pdfdoc = $pdf->Output('LECC'.$separator.'.pdf', 'S');
$attachment = chunk_split(base64_encode($pdfdoc));
// encode data (multipart mandatory)
$headers = "From: ".$from.$eol;
$headers .= "MIME-Version: 1.0".$eol;
$headers .= "Content-Type: multipart/mixed; boundary=\"".$separator."\"".$eol.$eol;
$headers .= "Content-Transfer-Enconding: 7bit".$eol;
$headers .= "This is a MIME encoded message.".$eol.$eol;
// message
$headers .= "--".$separator.$eol;
$headers .= "Content-Type: text/html; charsrt=\"iso-8859-1\"".$eol;
$headers .= $message.$eol.$eol;
// attachment
$headers .= "--".$separator.$eol;
$headers .= "Content-Type: application/octet-stream; name=\"".$filename."\"".$eol;
$headers .= "Content-Transfer-Encoding: base64".$eol;
$headers .= "Content-Disposition: attachment".$eol.$eol;
$headers .= $attachment.$eol.$eol;
$headers .= "--".$separator."--";
// send message
if(#mail($to, $subject, $message, $headers))
{
echo "<script type='text/javascript'> alert('mail sent');window.close();</script>";
}
else{
echo "<script type='text/javascript'>alert('mail not sent');window.close(); </script>";
}

Answer 1

I strongly believe that you somehow call this twice.