Send another mail if the email before was not openned

Hi! I´m trying to exploit the benefits of the "follow up" of open emails. I really want to create a automatation using the "opened" mark of emails as a trigger. Is there the possibility of sending an email IF the email before was not openned, using the follow up of openned emails?

Also, is there the possibility of having a follow up of the emails that got an answer by the lead? It will be very usefull using this follow up as a trigger for other actions.