Not working

I installed this plugin, but it’s not working:
When I click on “follow” forum topics, I do receive notifications, but only because I’ve selected that from an existing forum topic. I don’t receive any notification when someone replies to my forum post, or just after me. Furthermore, I don’t receive any daily/ weekly summary, nor do I receive an email where there are new topics. Any solutions?

http://ww.wp.xz.cn/extend/plugins/buddypress-group-email-subscription/