In our community, we have a handful of people who still only use email to participate in discussions. It occurs to me that these people are missing out! They don’t know that people are liking their posts or what else is happening, including renaming or recategorization etc by mods.
Of course we do want these people to start logging in, but until they do - and as an encouragement to do so - it would be interesting to show them the latest notifications directly at the top of the digest email.
Another related thought is that it is overwhelming to log in after a few months and see that you have dozens (hundreds!) of new notifications. This number could be reset every time the digest is sent out, or at least after a certain age. A notification is not new if it’s 3 months old, even if I haven’t seen it.