I'd like an email digest notification option (no more frequent thanThat's a good point. Frequency is a dimension that has at least that one more possibility rather than just being an Immediate or Off toggle.
Maybe instead of the one-of-four selector I proposed in each category it should instead be a list of three selectors:
Groups I own,
Groups I moderate, and
Groups I neither own nor moderate.
For each of these select a delivery frequency: Immediate, Daily Digest, or Off.
On the subject of digests, maybe New Notifications should be added as a section at the bottom of the Daily Summary email, and the daily Digest email.