mail

实现 hook_mail

hook_mail($key, &$message, $params)

/**
 * Implements hook_mail().
 */
function common_mail($key, &$message, $params) {
  switch ($key) {
    case 'test': {
      $message['headers']['Content-Type'] = 'text/html; charset=UTF-8; format=flowed; delsp=yes';
      $message['body'][] = new \Drupal\Component\Render\FormattableMarkup($params['content'], []);
      break;
    }
  }
}

使用的时候

$message = \Drupal::service('plugin.manager.mail')->mail('common', 'test', $mail, $langcode, $params);

HTML 格式邮件发送