Free Tool
DNS Health Checker
Enter a sending domain to check its SPF, DKIM, DMARC, and MX records and get a deliverability health score, right in your browser.
No sign-up. Runs entirely in your browser using public DNS records — nothing is sent to our servers.
This checks the four core email authentication records using public DNS lookups, right in your browser — no paid third-party API. A domain freshly connected to a mailbox provider will show missing DKIM/SPF/MX until a mailbox is actually provisioned; that's expected, not broken.
DNS health checker, explained
What does this tool actually check?
Four core email authentication records: SPF (who's allowed to send for your domain), DKIM (cryptographic signing, checked against common provider selectors), DMARC (your enforcement policy), and MX (where mail for your domain gets delivered). Each is scored, weighted by how strict/correct the record is, into a single score out of 10 and a letter grade: green for A (9 to 10), amber for B or C (6 to 8.9), red for D or F (below 6).
Do I need a paid checker for this?
No. All of this is public DNS data anyone can look up, no paid API required. This tool runs the lookups directly in your browser using public DNS-over-HTTPS resolvers, free, no account needed.
Why does DKIM show missing even though I just set up my domain?
DKIM keys are generated per mailbox, not per domain — so DKIM can't exist until you've actually provisioned at least one mailbox on that domain through your mailbox provider. Missing DKIM on a domain with no mailboxes yet is expected, not an error.
My DMARC record shows a warning even though it exists — why?
DMARC has three enforcement levels: p=none (monitor only), p=quarantine, and p=reject. A p=none policy is valid but weak — it doesn't actually protect against spoofing, only reports on it. This tool scores it as partial credit and recommends graduating to quarantine or reject once your reports look clean.
Is my domain data stored anywhere?
No. Every lookup happens live in your browser via public DNS resolvers — nothing about the domain you check is sent to or stored on our servers.
Want your infra fully managed instead?
We build and operate cold email infrastructure — domains, mailboxes, DNS, and warmup — for B2B companies and agencies. If this tool flagged issues you don't want to fix by hand, let's talk.