I’m having the same problem. The email notifications worked when I first set the plugin up. I made no changes to the plugin or site and suddenly it stopped.
I finally fixed the issue – but only after deleting my entire database and site, and then reinstalling WordPress and reloading the datebase.
I’ve tried that several times. That also wouldn’t explain why, when I upload an image again, it still doesn’t appear as anything other than a box in the page editor or on the published page. This really has me puzzled… help!