Email Notification From All Authors’ Posts?

I’ve got a small business blog running, with several users. I want to be notified when anyone comments on *any* post, not just on my own, and I want everyone else to be notified for all comments as well (the traffic is small enough that this won’t be a problem, and it would save having to continually check the blog for updates). But the software only seems to allow me to get email notification for my own post comments. Am I missing something, or do I need to hack it. If so, how?