It will no longer allow someone to join. You can put in a new email on the widget, it will say that an email has been sent, but it never shows up–I’ve verified it’s not going to spam or other email folders.
I tried using the form on your site, and it seems to be working properly. I subscribed to your blog, and you can now see my email address in your subscriber list.
It’s worth noting that confirmation emails are only sent once, so if you previously attempted to subscribe but never clicked on the link in the confirmation email, you won’t receive a new email if you use the subscription form again today.
You can confirm your pending subscription here:
https://subscribe.wordpress.com/
If you’d like, you can send me an email via this contact form and mention this thread, as well as a few examples of the email addresses that didn’t receive a confirmation email. I’ll be happy to take a look at our email logs to find out what happened.
The second problem is that for the few subscribers that I have, the featured image will not display in the email–it just shows a weird symbol where the image should be.
Jetpack Subscription emails do not include the featured image. That’s something we might add in a future Jetpack release, but we haven’t done so yet.
You shouldn’t see any weird symbol instead, though, unless that symbol is also added to the post content on your site.
Since I subscribed to your site, I’ll receive a notification of your next post. When I do, I’ll check that weird symbol and let you know what I find.