Confirm DMARC, DKIM and SPF alignment
Authentication must be present and aligned with the domain recipients see. Audit every sending platform, SPF lookup limits, DKIM signatures, return paths and DMARC reports before raising enforcement.
Look for a reputation event
A sudden increase in volume, a new domain or IP, a blocklist event, complaint spike or cold-audience campaign can change placement quickly. Compare sending changes with bounce, complaint and engagement trends by mailbox provider.
Audit acquisition and list hygiene
Old lists, scraped contacts, weak validation and long-term inactivity produce spam traps and low engagement. Suppress risky cohorts, fix the acquisition source and add recurring rules so the same contacts do not return.
Warm infrastructure with engaged recipients
New or recovered infrastructure should ramp gradually, starting with recipients who recently demonstrated interest. Consistent volume and strong engagement give mailbox providers evidence that wanted mail is being sent.
Measure inbox placement, not just delivery
A delivered event only means the message was accepted, not that it reached the primary inbox. Use seed testing, postmaster data, DMARC reports and campaign engagement together to see where placement changes.