Free tool
Domain health score
Enter a domain and get one score out of 100. Each check is pass, warn or fail, with the record we found and the fix when something is wrong.
Seven checks, one score out of 100
Each check earns its weight in points. A Spamhaus listing or a missing SPF or DMARC record caps the score.
- MX15 points
- SPF20 points
- DKIM15 points
- DMARC25 points
- BIMI5 points
- MTA-STS5 points
- Spamhaus DBL15 points
Quick answer
What this tool checks
MX. The domain must publish mail exchangers that resolve. No MX means it cannot receive mail and most providers will bounce.
SPF. One v=spf1 record, 10 DNS lookups or fewer, and no +all or ?all. We reuse the same evaluator as the SPF checker.
DKIM. A scan of common selectors, including Lumail’s. One usable public key is enough. A revoked key fails; no key on the common selectors only warns, since many providers use custom selectors.
DMARC. Policy strength, rua reporting and inherited parent policy. p=none only monitors; quarantine and reject protect the From domain.
BIMI and MTA-STS. BIMI is informational and only helps once DMARC is enforced. MTA-STS is a cheap TXT check that mail servers use to require TLS.
Spamhaus DBL. A listing caps the score so a listed domain can never show as good, even if the rest of the DNS looks fine.
How the score is weighted
| Check | Weight | What fails it |
|---|---|---|
| MX present | 15 | No MX record |
| SPF | 20 | Missing, +all, duplicates, or more than 10 lookups |
| DKIM | 15 | Revoked key (no key on common selectors warns) |
| DMARC | 25 | Missing, malformed or duplicated record |
| BIMI | 5 | No BIMI record (informational) |
| MTA-STS | 5 | No _mta-sts TXT |
| Spamhaus DBL | 15 | Domain listed |
| Cap: listed | max 39 | Never “good” |
| Cap: SPF or DMARC fails | max 49 | Never “good” |
| Any SPF, DKIM or DMARC failure | — | Never “good” |
How to fix common issues
No SPF or DMARC
Publish one SPF record that lists every sender and ends with ~all, then a TXT at _dmarc.yourdomain.com with v=DMARC1; p=none and a rua mailbox. Lumail writes and verifies these for every sending domain.
Listed on Spamhaus
Stop sending, request a delisting from Spamhaus, and fix the content or stolen-account cause they name. A listing here caps the score until the domain is clean.
SPF too many lookups or +all
Use the SPF checker to see which includes burn lookups. Remove unused senders and change +all to ~all.
No DKIM key found
Copy the selector from a sent email’s DKIM-Signature header and check it on the DKIM checker. Provider-specific selectors are often not on the common list.
Frequently asked questions
What is a good domain health score?
80 or above is good: MX, SPF, DKIM and a DMARC policy are in place and the domain is not listed. 50 to 79 needs work. Below 50, or any cap from a listing or missing SPF/DMARC, is poor.
Why is a listed domain capped?
Mailbox providers treat a Spamhaus DBL listing as a hard reputation signal. Authentication records do not override it, so the score cannot look healthy until the listing is gone.
Does this replace a mail tester?
No. This reads public DNS and one domain blocklist. A mail tester scores a real message: content, authentication alignment and the IP path. Use both.
Does Lumail set these records for me?
Yes. Adding a sending domain generates SPF, DKIM and DMARC and checks that they resolve. Use “Fix it automatically with Lumail” to start.
Does this tool contact my mail server?
No. It reads public DNS and Spamhaus DBL only, with a timeout so one slow resolver cannot hang the page. Nothing is sent to the domain.
Related tools and guides
- GlossaryWhat is SPF?How receivers check which servers may send for a domain.
- GlossaryWhat is DMARC?The policy that ties SPF and DKIM to your From domain.
- DocsAuthenticate a sending domainSet up SPF, DKIM and DMARC for Lumail.
- Free toolSPF checkerCount SPF lookups and flag weak policies.
- Free toolDKIM checkerFind a domain’s DKIM keys by selector.
- Free toolDMARC checkerRead the DMARC policy and what to tighten.
- Free toolMail testerSend a real email and get a score out of 10.
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