What is fatigue scoring?

Fatigue scoring is a way of tracking how close each subscriber is to the point where they stop engaging or start opting out. Before they actually do it. Instead of applying the same frequency to everyone, fatigue scoring assigns each contact a score that rises when they receive emails without engaging, and drops when they click or open. High fatigue scores signal it's time to pull back before the subscriber unsubscribes or marks you as spam.

The scoring logic typically works like this: each email sent without a click adds points to the fatigue score. A non-open might add more points than an open-without-click, depending on how you weight it. A click resets the score partially or fully. Subscribers who hit a defined threshold, say, a score above 15 on a 20-point scale, get moved to a reduced-frequency segment automatically, or suppressed from promotional sends while still receiving transactional messages.

The value over a simple "no engagement in 90 days" rule is responsiveness. A subscriber who opened your last eight emails but didn't click any of them is building fatigue that a recency-only rule would miss. Fatigue scoring catches that drift earlier and lets you intervene with lighter cadence or a preference prompt before you lose the subscriber entirely. It's particularly useful for high-frequency senders, daily or multiple-per-week programs, where the standard 90-day recency window moves too slowly to prevent damage.

Implementation varies by ESP. Some platforms, particularly Klaviyo and enterprise tools like Salesforce Marketing Cloud, have built-in engagement scores you can use as a proxy for fatigue. Others require a custom scoring model using a counter field and automation logic. Start simple: a field that increments on each unopened send and resets on click. Set a suppression threshold, monitor engagement trends by score band for a few weeks, and adjust the threshold if the model is suppressing too aggressively or not aggressively enough. See list hygiene for how fatigue scoring fits into broader list health practices.