Generate PDF and send mail
Ok First off all Installing drupal TCPDF module is not enough to have working pdf-s. We are also obligated to download TCPDF libray from http //www.tcpdf.org/ and place it to drupal files so that library will be avaible like this 


  C:\xampp\htdocs\drupalac_gw\sites\all\libraries\tcpdf\tcpdf.php


above will solve:


  Fatal error: Call to a member function DrupalInitialize() 


With working pdf library sending emails with attachments is easy i have like this:

drupal_mail('module', 'notice', "to@mail","", array(), "from@mail");


where:

function module_mail($key, &amp;$message, $params) {
  $attachment = array(
    'filecontent' =&gt; generatePdf("S"),
    'filename' =&gt; 'example-filename',
    'filemime' =&gt; 'application/pdf',
  );

  switch($key) {
    case 'notice':
      $langcode = $message['language']-&gt;language;
      $message['subject'] = 'example submission from ';
      $message['body'][] ='my example.';
      $message['params']['attachments'][] = $attachment;
      break;
  }  
}


And where:

function generatePdf($where="S") {
  $pdf = tcpdf_get_instance();

  $pdf-&gt;setFontSubsetting(true);

  // set font
  $pdf-&gt;SetFont('freeserif', '', 12);

  $pdf-&gt;SetHeaderData(PDF_HEADER_LOGO, PDF_HEADER_LOGO_WIDTH, PDF_HEADER_TITLE.' 008', PDF_HEADER_STRING);

  // set header and footer fonts
  $pdf-&gt;setHeaderFont(Array(PDF_FONT_NAME_MAIN, '', PDF_FONT_SIZE_MAIN));
  $pdf-&gt;setFooterFont(Array(PDF_FONT_NAME_DATA, '', PDF_FONT_SIZE_DATA));

  // set default monospaced font
  $pdf-&gt;SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);

  // set margins
  $pdf-&gt;SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP+10, PDF_MARGIN_RIGHT);
  $pdf-&gt;SetHeaderMargin(PDF_MARGIN_HEADER);
  $pdf-&gt;SetFooterMargin(PDF_MARGIN_FOOTER);

  // set auto page breaks
  $pdf-&gt;SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);

  // set image scale factor
  $pdf-&gt;setImageScale(PDF_IMAGE_SCALE_RATIO);
  return $pdf-&gt;Output('example_008.pdf', $where);
}


Above is now my working example :)