<b>The five metrics that predict a deliverability problem early</b>

<b>The five metrics that predict a deliverability problem early</b>
Resources for watching the right numbers, not the vanity ones.

🧪 Tests
— Google Postmaster spam-rate dashboard — keep complaints under 0.1%; 0.3% is the Gmail cliff, so 0.1% is your real alarm line.
— Engagement-trend monitoring guides — falling open rates precede placement drops by weeks; it's your earliest warning.
— Bounce-classification docs (hard vs soft) — rising soft bounces often mean a reputation throttle, not bad addresses.
— Validity / Return Path sender-score primers — a single number that's blunt but useful as a trend line.

Picked because by the time opens crater, the damage is weeks old — these catch it upstream.

Saved you ~2 hours of diagnosing a fire after it spread.