Issue #3344346: Translate email notification to recipient's preferred language

modules/private_message_notify/src/Service/PrivateMessageNotifier.php

@@ -122,6 +122,7 @@ class PrivateMessageNotifier implements PrivateMessageNotifierInterface {
           ]);
           $notification->set('field_message_private_message', $message);
           $notification->set('field_message_pm_thread', $thread);
+          $notification->setLanguage($member->getPreferredLangcode());
           $notification->save();
 
           $this->messageNotifier->send($notification);