Sendy

I’ve been using Sendy for years. While I love it now, there was a bit of learning curve at first, and I had to integrate a few other tools (I.e. Sendy lacks a great WYSIWYG visual HTML editor). If you’re willing to take the time to learn its idiosyncrasies, it will likely save you a lot of email marketing money in the long run.

That said, if you’d rather not deal with the nitty-gritty of self hosting, and your needs are simple, check out SendFox.