Gravity Forms MyMail Add-On is a premium WordPress plugin That integrates MyMail Newsletter Plugin with Gravity Forms to subscribe users with a Gravity Form.
Requires the MyMail Newsletter plugin >= 1.5 and the Gravity Forms plugin. Download: http://wordpress.org/extend/plugins/gravity-forms-mymail-add-on/
MyMail Newsletter Plugin: http://codecanyon.net/item/mymail-email-newsletter-plugin-for-wordpress/3078294?RX_c=shorturl&RX_s=rxa.li&RX_m=link&ref=revaxarts