Cold Email Deliverability: Complete DNS Configuration Guide

Why Deliverability Matters

You can have the best cold email strategy in the world, but if your emails land in spam — nobody will read them. Deliverability is the foundation of effective cold mailing.

In this guide, I'll show you how to configure your domain's DNS so your emails reach the inbox.

SPF (Sender Policy Framework)

SPF tells mail servers "which servers are authorized to send emails from your domain."

How to Configure SPF

Add a TXT record in your domain's DNS:

``` v=spf1 include:_spf.google.com include:spf.your-smtp.com ~all ```

Rules:

• Use `~all` (soft fail) instead of `-all` (hard fail) at first — more flexibility
• Don't add too many `include` directives — limit is 10 DNS lookups
• Regularly verify your configuration

DKIM (DomainKeys Identified Mail)

DKIM adds a digital signature to each email, proving it actually came from your domain.

How to Configure DKIM

1. Generate a key pair (private and public) in your SMTP or email platform 2. Add a TXT record in DNS with the public key 3. Record name: `default._domainkey.yourdomain.com` 4. Value: `v=DKIM1; k=rsa; p=YOUR_PUBLIC_KEY`

DMARC (Domain-based Message Authentication, Reporting & Conformance)

DMARC tells mail servers what to do when SPF and/or DKIM fail validation.

How to Configure DMARC

Add TXT record: `_dmarc.yourdomain.com`

``` v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com; pct=100 ```

DMARC policy levels:

• `p=none` — monitoring (blocks nothing)
• `p=quarantine` — suspicious emails go to spam
• `p=reject` — suspicious emails are rejected

Start with `p=none`, collect reports for 2-4 weeks, then move to `p=quarantine`.

Domain Warmup

A new domain has no reputation. "Warmup" is the process of gradually increasing send volume to build a positive sending history.

Warmup plan:

• Week 1: 5-10 emails per day
• Week 2: 20-30 emails per day
• Week 3: 50-100 emails per day
• Week 4: 100+ emails per day + bounce rate monitoring

Monitoring

Use tools like Google Postmaster Tools, MXToolbox, or GlockApps to monitor domain reputation and deliverability.

Conclusion

Deliverability isn't a one-time setup — it's an ongoing process. Regularly check SPF, DKIM, DMARC, and your domain reputation. Keep your list clean (remove bounces), and your emails will land where they should.