Hi @immeriiti,
I do not believe we received a contact request or support request on our support website yet. We’ll be happy to help you there and troubleshoot it.
From what we can tell, based on experience, but by no means could it be the cause, is that your hosting might be blocking this for various reasons or there’s a misconfiguration in the email setup in Newsletters > Configuration. There might be another third party plugin interfering with our plugin.
We once had a customer whose hosting was preventing this from working correctly (we still do not know the cause), and once he joined our hosting, everything worked as intended. Many hosting companies meddle so much with WordPress that WordPress starts to have problems here and there. We leave things as they are and let WordPress be WordPress.
We know that our plugin works as we have dozens of thousands using the free and paid versions. We use it for our own sites as well with autoresponders and scheduled monthly newsletters.
We hope we can help you use it as well!