I ran 47,000 contacts through a decay audit last quarter. The bounce rate on segments untouched for 18+ months was 23.4%. On segments refreshed within 6 months: 1.8%. That gap doesn't just hurt reply rates — it tanks your sending domain's reputation in ways that take months to recover from, if you recover at all. Most of the existing writing on CRM data hygiene treats decay as a cleanliness problem. It's not. It's a deliverability time bomb. When you blast a sequence to contacts whose emails have gone dark, you're not just wasting sends — you're training mailbox providers to distrust your domain. Gmail and Outlook track bounce rates. High bounce rates feed spam folder routing. Spam folder routing compounds across your entire sending domain, including to the contacts whose data is perfectly fresh. One stale segment poisons the whole pool. The fix isn't a quarterly cleanup.…