Dear Stefano,
It seems that users can’t unsubscribe from the newsletter.
I’ve checked on three different WordPress installations.
The behavior is the same.
Here are the steps that I take:
1. Enter e-mail from the Newsletter widget and press subscribe.
2. Open the received confirmation e-mail and confirm subscription.
3. From the Welcome aboard e-mail click the unsubscribe link and confirm that I want to unsubscribe by clicking the link on the page: wp-content/plugins/newsletter/subscription/page.php?nm=unsubscription
4. After clicking the link I get the “Your subscription has been deleted. Thank you.” on the next page
5. However I don’t receive an email confirming that I unsubscribed successfully and when I go to Newsletter -> Subscribers I can still see the same e-mail address with status CONFIRMED.
Is there anything I am missing out?
Thank you in advance.