gistfile1.php

<?php
    send_email_template('contacto_empresa_no_registrada', $attrs = array(
      'title' => 'Alguien pide informacion de su franquicia en nuestro portal Franquiciame.com',
      'email' => $companyUnregistered
    ));

function render_email_template($template_name, $attrs = array(), $cached = true) {

  include 'Twig/Autoloader.php';
  Twig_Autoloader::register();

  $parameters = array();

  if($cached == true) {
    $parameters['cache'] = __DIR__.'/inc/emails_contents/cache';
  }

  $loader = new Twig_Loader_Filesystem(__DIR__.'/inc');
    $twig = new Twig_Environment($loader, $parameters);

  return $twig->render('emails_contents/'.$template_name.'.html', $attrs);
}

function send_email_template($template_name, $attrs = array(), $cached = false) {

  $template = render_email_template($template_name, $attrs, $cached);

  add_filter( 'wp_mail_content_type', array('Boletin', 'set_html_content_type' ));
    wp_mail($attrs['email'], $attrs['title'], $template);
  remove_filter( 'wp_mail_content_type', array('Boletin', 'set_html_content_type' ));
}