Email everyone?

I have a simple bbpress install and I would like bbpress to email everyone who is a user. I thought that is what this plugin would do. It installs fine, but when I post new topics in my forums, my users don’t get any emails. I don’t want the users to have to subscribe – by being a user, they have subscribed for this purpose.

Thanks!

http://wordpress.org/extend/plugins/bbpress-notify/