I've been researching WordPress newsletter plugins for about a year. Spent a bit of money on plugins that just never did the trick.
Finally found WYSIJA and I have to say it's one of the best out there! Easy to integrate, works out of the box with a few minor setting updates and very easy to create newsletter Themes (or use the free ones they offer with the plugin). My email marketing just got a whole lot easier!
The support is second to none, as well.
What you GET is just awesome!
Kelley Rao, President