Mailbag lets you quickly and easily add MailChimp or Campaign Monitor email forms to your posts or pages with a shortcode.
Dead Simple Email Subscriptions
Mailbag integrates both MailChimp and Campaign Monitor API's to provide you with email subscription forms you can easily drop into your posts or pages. Simply add your API key, choose a list to subscribe users to, and add a shortcode to your page.
Mailbag ships with minimal front-end styles that can be disabled if you'd rather inherit styles from your theme. Customize the form easily with unique CSS selectors.