andriyun

<?php
/**
 * See original implementation http://cgit.drupalcode.org/mailsystem/tree/src/MailsystemManager.php#n60
 */
// Switch the theme to the configured mail theme.
$theme_manager = \Drupal::service('theme.manager');
$mail_theme = '[your theme name]';
$current_active_theme = $theme_manager->getActiveTheme();
if ($mail_theme && $mail_theme != $current_active_theme->getName()) {
  $theme_initialization = \Drupal::service('theme.initialization');