Looking for a plugin that notifys all users on anything new on the blog

Hi,
I’m looking for a plugin or a combination or plugins if thats necessary.
What I want to do is that I want all users on the blog to get a mail if anything happens on the blog, a new post, a new comment is the most important. I have looked around for one that could to this but haven’t really found one that works for both new posts and comments. If there isn’t any plugin that can do this alone, does anyone have a combination of two that works well together?