Auto Newsletters Send Immedeately don’t work

Thank you for the plugin, it’s really great and user-friendly. I got a problem though.

The Send Immediately for the auto newsletters don’t work. I made 3 test subscribers with my own emails, all 3 received confirmation letters and got “confirmed” status in my admin subscribers list.

I also made a custom newsletter (auto send immediately, activated, My first list, WordPress Users).

Now i create and publish a new post – and nothing happens. No one of my 3 subscribers gets the newsletter, not in spam, not 30 mins after the post is published. What am i missing?