Struggling with low opens? Inbox placement depends on four pillars: authentication, reputation, audience quality, and message quality. Use this practical playbook to recover from spam placement and protect sender reputation.

1) Authenticate Your Domain (SPF, DKIM, DMARC)

Add SPF and DKIM first, then start DMARC with p=none to monitor reports. Align your visible From domain with SPF/DKIM domains (domain alignment). Tighten gradually to quarantine or reject.

SPF: keep DNS lookups < 10; end with -all when stable.
DKIM: use 1024/2048-bit keys; rotate selectors (s1, s2).
DMARC: begin p=none → move to quarantine/reject after you verify alignment.

Starter DMARC (monitoring)

Host: _dmarc
Type: TXT
Value: v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com; ruf=mailto:dmarc@yourdomain.com; fo=1; pct=100; sp=none

Upgrade to p=quarantine or p=reject after 1–2 weeks of clean reports.

2) Repair Sender Reputation

Reputation is behavior-based. Lower volume temporarily, then rebuild trust with highly engaged recipients first.

Pause cold cohorts for 7–14 days.
Send only to high engagers (opened/clicked in last 14–30 days).
Increase volume 20–30% every few days if no blocks/complaints.

3) List Hygiene & Segmentation

Remove hard bounces immediately; suppress repeated soft bounces (3–5 attempts).
Sunset 60–90 day non-openers; run a re-engagement campaign first.
Segment by intent: new, active, slipping, dormant; tailor cadence per group.

4) Message Quality: What Filters Look For

One clear CTA, keep external links < 4, avoid public shorteners.
Include a real postal address + one-click unsubscribe.
Add a plain-text part closely matching the HTML.
Avoid spammy phrases, image-only emails, and mixed languages.

5) Cadence & Timing (B2B)

Tue–Thu, 9:30–11:30 or 13:30–16:00 recipient-local. Avoid big spikes; ramp predictably.

6) Tracking Domain & TLS

Use a branded tracking domain (CNAME) with TLS. Keep all links HTTPS.

Warmup Ramp (Example)

Days	Daily Sends	Audience
1–3	50–150	Opened last 14 days
4–7	200–400	Opened last 30 days
8–14	600–1200	Clicked in 90 days

Quick Win Checklist

Authenticate: SPF + DKIM + DMARC (p=none to start).
Reduce volume: send to engaged cohorts only.
Clean list: remove bounces, sunset inactives.
Tidy content: clear CTA, 2–3 links, plain text part.
Track: branded CNAME, HTTPS, no open-link farms.
Ramp: 20–30% increments; monitor for blocks.

FAQ

Why am I suddenly in spam? Usually volume spikes, a risky list, or broken DNS after a change. Roll back volume and verify SPF/DKIM alignment.

How fast can I recover? 1–3 weeks with reduced volume and better segmentation; faster if authentication was the only issue.

Next: read How to Send Bulk Emails Safely or compare tools in AutoMailiQ vs Mailchimp.

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