Getting error any error in the Subscription Box?
1. Open JavaScript file from below mentioned location.
wp-content\plugins\email-posts-to-subscribers\widget\widget.js
2. Go to line 70, 71
3. Remove the comment for that two lines.
From
//alert(xmlHttp.readyState);
//alert(xmlHttp.responseText);
To
alert(xmlHttp.readyState);
alert(xmlHttp.responseText);
And try it again, now you can see the actual error in the alert box.
How to update Subscription Box style?
You have separate CSS file for Subscription Box styling. Please find the CSS file from the below mentioned path.
wp-content\plugins\email-posts-to-subscribers\widget\widget.css
Plugin Live Demo
http://www.gopiplus.com/work/2014/03/28/wordpress-plugin-email-posts-to-subscribers/
Plugin Official Page
http://www.gopiplus.com/work/2014/03/28/wordpress-plugin-email-posts-to-subscribers/