DomainBurn
№ 001 · 2026
A 10-second cold email audit

Your cold email isn't
failing. It's getting burned. By DNS records you set up once and forgot.

DomainBurn runs eight forensic checks against your sending domain — SPF, DMARC, DKIM, blacklists, the works — and tells you, in plain English, exactly which one is killing your reply rate this week.

No signup · No test email sent · DNS only

Find out if you're burned

./scan — paste a sending domain, hit return
SPFDMARCDKIMMXMTA-STSBIMIRBLsage
resolving dns records…

The math behind a burned domain.

Cold outbound teams spend weeks A/B testing subject lines while their DNS quietly tanks every campaign. Here's what we measured scanning 500 active sending domains last month:

73%
Had DMARC misconfigured or missing. Since Feb 2024, Gmail throttles bulk senders without it.
n=500
61%
Were still signing with 1024-bit DKIM keys. Mailbox providers downrank these in 2026.
n=500
94%
Had no MTA-STS policy published, allowing TLS downgrades in transit.
n=500
£8.7k
Median pipeline lost per blacklist incident, per agency client we surveyed.
n=42

Three reasons this isn't just another mail tool.

i.

Cold-specific scoring.

Mail-Tester and MXToolbox were built for marketing newsletters and IT teams. Their grades don't reflect what kills outbound. We weight DMARC enforcement, key length, and RBL exposure the way Gmail's spam classifier actually does in 2026.

ii.

No seed list theatre.

Tools that ask you to send a test email to seed addresses give you a 24-hour-old snapshot. We read DNS directly — same data Gmail uses — so the audit is always real-time. Ten seconds, not next morning.

iii.

Built to alert, not to dashboard.

You don't want another tab. You want a Slack ping the moment your SPF breaks or your IP lands on Spamhaus. Monitoring runs daily; alerts fire in the channel where your team actually lives.

Pricing — one for each shape of team.

The free scan is genuinely free, forever. Paid tiers exist for one reason: you can't be in the inbox to notice when DNS breaks at 2am.

Free
For checking your own domain before sending a campaign.
  • One scan per day
  • All eight deliverability checks
  • No history, no alerts, no team accounts
£0
Run a scan
Solo
For founders and SDRs running their own outbound.
  • Ten domains, monitored daily
  • Slack and email alerts on regression
  • Full scan history and PDF exports
  • Annual paid — 20% off
£29/mo
Agency
For shops running outbound across many client domains.
  • Fifty domains, monitored daily
  • White-label PDF reports for clients
  • API access — 10k calls per month
  • Webhook alerts and priority support
£99/mo
White-label
For agencies who want to sell deliverability as a service under their own brand.
  • Unlimited domains and API calls
  • Your domain, your logo, your colours
  • Multi-tenant client portal
  • Direct line to the founder
£299/mo

Questions, briefly answered.

How is this different from MXToolbox?
MXToolbox is a generalist diagnostic with a UI from 2008. It tells IT teams about every mail-related record in existence. DomainBurn is opinionated: it scores you specifically as a cold sender in 2026, ignores noise, and tells you which fix moves the needle.
Do you send a test email to grade me?
No. Every check is pure DNS, read from Cloudflare's resolver. We never touch your inbox or your mail server, so the scan is faster, more private, and runs anywhere.
Which blacklists do you check?
Free scans hit four major lists (Spamhaus ZEN, SpamCop, Barracuda, SORBS). Paid monitoring sweeps fifteen — including the niche ones that Gmail's classifier weights heavily.
Annual discount?
Yes — twenty percent off any paid tier, billed annually. Email after signup to switch.
Who built this?
A founder who got tired of watching domains get burned by silent DNS misconfigs. Built solo. Email goes straight to the inbox of the person who wrote the code.