I test drove several email services before deciding to go with Mad Mimi. They provide enough features to send a good looking email campaign, with a very intuitive interface. There aren't a bunch of bells and whistles, and you don't need to earn a Phd....
Wordfly lets you create beautiful templates and easily automate emails.
I found that marketing automation and drip campaigns were a bit difficult to setup, and there wasn't a clear explanation of what was available in the free vs paid version.
There may be some limitations of a user does not know how to code, which can be problematic.