This plugin sends mail using ajax and gather email list, have options page, custom css and form design usability.
This plugin will help you to send mail using ajax from your wordpress site. You can design your own contact form from the admin. There will be a email list waiting for your review. There are several options for the contact that you can update later. You just need to put shortcode [ajaxcf] in any page/post. There is also custom css area in the admin.