What is list health?

List health is a per-channel condition check on your messaging audience: is this list still worth mailing at the current pace? It combines one fast-moving signal — the unsubscribe rate averaged over the last three sends — with two slow ones, the lifetime average open and click rates, and turns the fast one into a status: ALERT when recent unsubscribes exceed 1%, HEALTHY otherwise.

Formula

recent unsub rate = avg(unsubscribes ÷ sends) over the last 3 sends
status            = ALERT if recent unsub rate > 1%, else HEALTHY

Worked example

An email channel shows a lifetime open average of 31%, click average 2.4%, and a recent unsubscribe rate of 1.4% — ALERT. The lifetime gauges say the list has been good; the three-send window says something just changed: a frequency jump, an off-brand offer, a stale segment re-mailed. The short window is the point — the status reacts to what you did last week, not to your yearly average.

How Saldo Metrics computes it

v_list_health computes one row per (channel, medium) from fact_messaging_performance. The recent unsubscribe rate averages the per-send unsubscribes ÷ sends of the three most recent sends; the open and click gauges average each send's rate over the channel's whole history. Email and SMS are scored separately, and since SMS has no open tracking, its open gauge is simply absent rather than zero. The 1% threshold is fixed and matches the unsubscribe highlighting on the campaign table, so the status and the table never disagree.

Why it matters

Deliverability failure is expensive and slow to repair: mailbox providers score senders on engagement and complaints, and a burned domain takes months to recover. List health is the tripwire in front of that cliff — three sends of elevated unsubscribes is early enough to change course before reputation damage compounds.

Common mistakes

• Reading HEALTHY as permission to scale sends. The status only checks unsubscribes; a list can read HEALTHY while its click gauge decays — check all three numbers.
• Ignoring an ALERT because revenue was good. The revenue is booked; the list damage recurs on every future send.
• Expecting the status to smooth over outliers. Three sends is a deliberately twitchy window; one catastrophic campaign can trip it alone. That is a feature — investigate the campaign rather than the metric.

Where you see this in the app

Marketing → Messaging, as the list-health gauges and status at the top of the tab.