Hey there jhdesigns,
To clarify, this plugin is intended to serve the purpose of adding a signup form to your MailChimp list, onto a WordPress site. The functionality being described of blog posts being sent seems to be more in line with our RSS-driven campaign feature, which is not related or dependent on this plugin.
If you're looking to utilize that feature instead, I'd recommend checking out this help article here:
How can I create an RSS-Driven Campaign?: http://eepurl.com/iDlQ
if you have additional questions, the best bet would be to reach out to the MailChimp support team on the right-hand side of the article.
If I've misunderstood the question and you are seeing an issue with the plugin's sign up form, feel free to post here and I'd be happy to take a closer look!