The Team needs to integrate a Captcha (Silent Recaptcha would work also)!!
THIS IS THE ONLY WAY!! Antiflod is no option or solution. The only way to stop it is to deactivat the plugin.
I will not renew my subscription in case there is a Captcha integrated.
So this makes me sad about this plugin. There is no quick solution if there is a big big problem like this!
Please let me know if you get fixed the spam subscription problems. This happens also to me and there is no way to stop it. I deactivated the plugin now. Would be great if the developer make a recaptcha integration option to the plugin.