This email type may also be referred to as a “rollup” email or a “summary” email. The idea is to send a single email that summarizes what’s happened in your app over a period of time.

The best way to do it today is a Loop with an event trigger set to fire “every time” with an event payload containing the updated property you’d like to send.

Then at the end of the day, week or month you can trigger a digest email with a summary of the events that happened.

Here’s more on triggering loops: https://loops.so/docs/loop-builder/loop-triggers

And here’s the API: https://loops.so/docs/api#events