Acumbamail

We've been using it daily for our business for over a year now. I love that it uses the highly-capable BEE editor that is one of the most advanced email editors out there. You can also import your custom html templates from dragit or use a html block in the email, if you want to get more advanced. At first, we did have some deliverability issues, but they must have changed sending servers, and we haven't had issues in awhile with that. It integrates with so many platforms now, and you can use their SMTP, which is a great bonus. Although, if you have many subscribers and send with their SMTP, the sending speed is not very good compared to a service like Amazon SES.