How do you fix churn driven by notification overload?

We built automated alerts, summaries, and email digest triggers thinking we were keeping users engaged. But cancellation feedback showed the exact opposite.

Instead of bringing users back our notifications were creating inbox noise, causing users to mark us as spam or cancel just to clear their mental clutter. They liked the product, but hated the daily noise around it.

For founders who have optimized re-engagement: how do you design smart notification frequencies that build habits without causing fatigue?