A simple newsletter

I would like to have an newsletter for my site, now I found few plugins that do it, but the problem is, it require subscribers to registed to the site this could work, but it require too much work from the user part, I only want the users to have to give their name and email, with out having to chose a password or do anything else, just a very simple form.
So what I’m looking for is, either a newsletter plugin that doesn’t require subscribers to registed to the site, or a way to let user registed to the site with out having to chose a password..

Any help would be appertied.