Constant Contact plugin for automatic WP update mails

I have just installed the WP plugin for Constant Contact and connected our WP blog to our Constant Contact account. We would like to use this plugin to send out a neatly formatted email to our subscriber list every time a new post is placed on the site. I cannot seem to find out how to do this. I can use the plugin to send self-initiated emails, but can’t seem to get automatic updates to go out whenever a new post is placed on the site.

Can anyone help?

https://www.ads-software.com/plugins/constant-contact-signup-form-widget/