Organize "comment spam" notifications via a digest option

We're previewing Crucible and the one thing that the engineers are really complaining about is the volume of email notifications they get. Every single comment made gets emailed out to every single engineer. This overwhelms the inbox pretty quickly. They do want to know that comments have been made so they can review and participate in a discussion, but the immediate email that goes out on any comment is really noisy. Same thing for a moderator for a review with 10 people knowing about every action each of them does.

My feature request is to have a digest option that rolls up summaries of each of the changes made and puts it out in a single email. I'd recommend using an interface similar to Jira's "Filter Subscription" screen to choose the frequency etc. Although I'd extend it to permit more frequent than daily updates (perhaps hourly etc).