I have been testing out the plugin before I use it on my site. I have a shared hosted site on Godaddy, and am using the latest version of wordpress.
I did try the following with both SMTP on and off.
When I send the test mail or newsletter things work fine. All is good.
But as soon as I try to use the forms for subscription, no emails go through. So I do not the confirmation mail (Double opt-in is enabled), nor do I get the activation email if I try to Resend it manually in the subscriber list.
Hi, that is a provider problem black listed by google. Ask godaddy about your problem, if an email is delivered to your mailbox it means the plugin is correctly moving it to your provider mailing service.