Do you have some alternatives you're looking at? Any special features?
So, you have to be a member of the blog to receive email notifications?
How about http://wordpress.org/extend/plugins/mailpress/ (I haven't tried it yet myself but it looks interesting)
I developed an email subscription plugin a few years back. I'm sure it can be changed to email when someone posts a new entry instead of sending emails out on certain days.
I know a few people who use wordpress, and you get the emails immediately when they make a post, but not sure what they use.
No, I know you can do that. What I meant was, with my plugin, I developed an email subscription plugin for someone a few years back. I then meant, I'm sure I can change it to email a list of people you have upon posting a new blog post.