jayveekay

@vandestouwe found the cause for this issue. Documenting it here too.

I had used a plus (+) sign in the email address to create test emails. For some reason, those did not work correctly and I could not confirm the subscription because of that. For “normal” email addresses the plugin works just great. So, this is not really a bug at all. Closing the issue.

Thanks! Sorry I missed that on the documentation. Really great plug-in! Exactly what I need because the topics are highly specific and not everyone is interested in all the topics.