<?php $thumb_url= https://www.100procentemail.com/labs/blogs/2017-10-25/interactiviteitanimatie-e-mail/attachment/header-2/($thumb-size);
	  $thumb_low = strtolower($thumb_url);
	  if (strpos($thumb_low, '.gif') === false) {
	  	$thumb_size = 'large';
	  } else {
	  	$thumb_size = 'full';
	  } ?>