How to send Email Invoice using | MPDF

 <?php

 require $_SERVER['DOCUMENT_ROOT'].'/pdf/phpmailer/class.phpmailer.php';

require  $_SERVER['DOCUMENT_ROOT'].'/vendor/autoload.php';

$to = "vijaychauhanssn@gmail.com"; 

$from = "vijaychauhanssn@gmail.com"; 

$subject = "sunject here"; 

$message = "<p>Msg here</p>";

$stylesheet = file_get_contents($_SERVER['DOCUMENT_ROOT'].'/assets/css/pdf.css');

$html = '<div id="printablearea">

<div class="container1" >

    body content here

    </div>

</div>';

$mpdf = new \Mpdf\Mpdf(['tempDir' => sys_get_temp_dir().DIRECTORY_SEPARATOR.'mpdf','default_font' => 'Arial', 'format' => 'A4']);

$mpdf->autoScriptToLang = true;

$mpdf->autoLangToFont = true;

$mpdf->WriteHTML($stylesheet, 1);

$mpdf->WriteHTML($html);

//call watermark content aand image

//$mpdf->SetWatermarkText('rajsahumahasabha.com');

$mpdf->showWatermarkText = true;

$mpdf->watermarkTextAlpha = 0.1;

//$mpdf->Output("invoice.pdf", 'F');

//$mpdf->Output();

// 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 = "invoice.pdf";

// encode data (puts attachment in proper format)

$pdfdoc = $mpdf->Output("", "S");

//$pdf->Output();

$attachment = chunk_split(base64_encode($pdfdoc));

// main header

$headers  = "From: ".$from.$eol;

$headers .= "MIME-Version: 1.0".$eol; 

$headers .= "Content-Type: multipart/mixed; boundary=\"".$separator."\"";

// no more headers after this, we start the body! //

$body = "--".$separator.$eol;

$body .= "Content-Transfer-Encoding: 7bit".$eol.$eol;

//$body .= "This is a MIME encoded message.".$eol;

// message

$body .= "--".$separator.$eol;

$body .= "Content-Type: text/html; charset=\"iso-8859-1\"".$eol;

$body .= "Content-Transfer-Encoding: 8bit".$eol.$eol;

$body .= $message.$eol;

// attachment

$body .= "--".$separator.$eol;

$body .= "Content-Type: application/octet-stream; name=\"".$filename."\"".$eol; 

$body .= "Content-Transfer-Encoding: base64".$eol;

$body .= "Content-Disposition: attachment".$eol.$eol;

$body .= $attachment.$eol;

$body .= "--".$separator."--";

// send message

mail($to, $subject, $body, $headers);

exit;

?>