System push notifications and emails have quit working

All of a sudden, system push notifications and email notifications have quit working. All was working fine but now they don't and I've tried to reset any work to figure out where the problem is but cannot find the problem.

I am getting emails that the cron job is working but i don't get any emails from the ES system. No conversation email notifications and no other email notifications. The emails show being sent in the Email Activity but no email is actually delivered.

Push notifications only work for conversations but not for any system notification.

Can you please take a look?
Thanks