Too many bots spam the register in the newsletter if any page with a newsletter widget is public.
SMTP is limited for small servers like mine, so this is a huge issue, as currently I am at 1265 bots registered
A way to only show or let registered users use the widget would be useful.
A way to add a captcha checkbox would be super useful too, because that actually stopped all the bots from registering on the website itself, so I think it would be good for the newsletter.
The other problem is having to unregister by hand; it would be useful if there were a check box-style selection to unregister multiple users at once, and a big red unsubscribe all button would be really useful.