Simple email management

Hi,

I just launched a blog, but I’m having some trouble find the right plugin. I want users to be able to log in easily and comment on posts. I also want to be able to send out a mass newsletter to everyone based on just a few attributes. That’s it. I don’t need anything complicated, just something simple that integrates with my blog subscribers.

I thought about using PHPList because I had a lot of success using that on a previous site I built, but unfortunately, it does not integrate with my wordpress users, so signing into phplist would not sign them in to comment on posts. I’d much much much prefer open-source. Thanks!