I've been searching around the plugins pages for a plugin or hack that will notify subscribed users via email that I've made a new post to my blog. There seem to be many plugins that will do this using their own e-mail subscription list, but what I really want is a checkbox option on each user's profile options page that says "notify me via e-mail whenever a new blog entry is made." That way, the plugin doesn't have to maintain a separate e-mail list and can just use the same database the rest of the site uses. Is there any plugin that can do this for me?