Cold email deliverability
Cold Email Deliverability Checklist
A practical cold email deliverability checklist: authentication, warm-up, list quality, reputation, and inbox placement before you scale.
Why this matters
Deliverability is the ceiling on every other metric. Emails that land in spam never earn an open, a click, or a reply — so no amount of great copy recovers a broken sending setup.
This checklist covers the technical and operational basics you should verify before scaling volume. It is a planning aid, not a guarantee of inbox placement.
The deliverability fundamentals
Core deliverability controls and why they matter
| Control | What to verify | Why it matters |
|---|---|---|
| SPF | Sender policy includes your sending sources | Stops spoofing; improves trust |
| DKIM | Signing is enabled and passing | Proves message integrity in transit |
| DMARC | Policy is published and aligned | Protects domain reputation and brand |
| Domain warm-up | Gradual volume ramp from new mailboxes | Builds sender reputation safely |
| List quality | Verified, relevant, opt-in-sourced contacts | Low bounce and complaint rates |
| Inbox placement | Test hits inbox, not spam/promotions | The real measure of deliverability |
Authentication before anything else
SPF, DKIM, and DMARC are the floor. Without them, mailbox providers treat your mail with suspicion regardless of content. Verify all three pass on the domains you send from, and align the From domain with your DMARC policy.
Align, don't just publish
A DMARC record only helps if your SPF and DKIM are aligned with the visible From domain. Publishing the record without alignment gives a false sense of safety.
Warm up and respect volume limits
- Ramp new mailboxes gradually — start low and increase daily volume over weeks.
- Keep within safe daily caps per mailbox; a single mailbox pushed past its limit risks reputation.
- Spread volume across multiple warmed mailboxes when you need scale.
- Pause and diagnose if bounce or complaint rates climb.
List quality protects reputation
Bounces and spam complaints are the fastest way to damage deliverability. Verify addresses before sending, target relevant contacts, and honor opt-outs immediately. A smaller, verified list outperforms a large, unverified one on every downstream metric.
Measure inbox placement, not just delivery
Delivery rate tells you the mail was accepted; inbox placement tells you it reached the primary tab. A message sitting in spam is delivered but ineffective. Test placement periodically and treat a drop as a deliverability signal, not a copy problem.
When to use the readiness check
Before a launch or a volume increase, run an inbox readiness review that scores domain setup, list quality, and copy risk together. It surfaces the issues most likely to suppress deliverability before they cost you replies.
Deliverability checklist before scaling
- SPF, DKIM, and DMARC are published, aligned, and passing.
- New mailboxes warmed up with a gradual volume ramp.
- Daily sending caps respected; scale across multiple mailboxes.
- List verified, relevant, and opt-out handled promptly.
- Inbox placement tested (inbox, not just delivered).
- Inbox readiness reviewed before each launch or volume increase.
Frequently asked questions
What is inbox placement rate?
The share of delivered mail that lands in the primary inbox rather than spam or promotions. Delivery rate counts accepted mail; inbox placement counts mail a person is likely to see.
How do I check cold email deliverability?
Verify SPF, DKIM, and DMARC, test inbox placement with a seed list, monitor bounce and complaint rates, and run an inbox readiness check before scaling volume.
What breaks cold email deliverability?
Missing or misaligned authentication, sudden volume spikes from new mailboxes, unverified lists with high bounces, spam complaints, and misleading subject lines or content.
Related pages
Model your own numbers
Use the ColdMailCalculator to turn assumptions into a reviewable forecast instead of a guess.
Forecasts and metrics ranges are educational estimates based on user-provided assumptions. Results are not guaranteed. This content is not legal, financial, deliverability, or business advice.