I personally use AWeber and recommend only AWeber to all my clients.

AWeber Quickly create and run your campaigns with powerful, easy-to-use email marketing tools. I recommend you sign up and start your mailing list today Another of my blog resources you can’t be without.

Aweber Coupon  

Aweber is one of the most popular email marketing solutions for bloggers. It lets you send emails, manage subscribers, and offer good tracking. Aside from that you can also send sequence of automatically delivered emails (autoresponder), automatically create emails from your newest blog posts, and target subscribers based on their action, location, etc with a single click. We use Aweber for some of our email lists. Also, you can easily Split Test optin forms template, headlines, headline color, text color, text of submit button, and much more.