I have found a bug using this plugin. There are 3 actually.
First being is, if you create a newsletter and save it, it saves a new draft/newsletter copy for same. Save it again and it will save a new version of it (even though both are updated I think).
Ideally the same newsletter should update but now after changes and saves it creates multiple copies of it.
Second, no matter how many time you save it or whatever kind of image you choose, I cannot add a background image to my newsletter what so ever, it shows in preview and even loads, save it and recheck or send newsletter, voila no background image at all.
Its not getting saved.
Third and most important, the email title is not updating at all. I saved it many times and used Email subject and title both yet just the title doesnt saves and uses "Default Email Title".
I am using Wordpress normal version 5.2.1
You can see my latest newsletter here