Hi everyone, this is Email Authentication Checker API. It checks a domain's email authentication records from a script or CI job. GET /v1/check?domain= reads the public DNS records over DNS-over-HTTPS and judges SPF, DMARC, DKIM, MTA-STS, TLS-RPT, BIMI and MX against the RFCs. The response has coded issues, a grade (A+ to F) and a score out of 100. Details: SPF follows include and redirect and counts DNS lookups against the limit of 10. DMARC covers policy, pct, rua/ruf, alignment and organizational-domain inheritance. DKIM checks the selector you pass with selector=, or ten common selectors if you pass none, and flags weak, revoked or testing-mode keys. MTA-STS, TLS-RPT and BIMI are checked as DNS records only. POST /v1/validate takes SPF, DMARC or DKIM record text and checks it offline, with no DNS lookups. Limits: the grade is a heuristic score of the published records, not proof that mail authenticates. It does not send mail, verify message signatures, test deliverability or fetch the MTA-STS policy file. Not finding a DKIM selector does not mean there is none. Results are cached for 15 minutes (fresh=1 bypasses the cache). Example: github.com returned grade D (68) on 2026-10-20, with SPF at 10 of 10 allowed lookups and two 1024-bit DKIM keys. Where to find it: RapidAPI, API.Market and APIHub (Zyla is in review). Product site: https://email-auth.glowhalo.org Feedback on the checks and the scoring is welcome.

Email Authentication Checker API

SPF, DMARC, DKIM and more from DNS, as a graded report

SPF, DMARC, DKIM and more from DNS, as a graded report