{"uid":"cap_WI-uKAcwoBjYHLs2y5wEE","slug":"email-dns-preflight-3c6db3ee","name":"Email DNS Preflight","description":"Pay-per-call email syntax and public DNS/mail posture preflight. No mailbox-level SMTP claim.","url":"https://email-dns-preflight-x402.copper-crate.workers.dev/v1/email/preflight?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"queryParams":{"type":"object","required":["email"],"properties":{"email":{"type":"string","maxLength":254,"description":"Email address to preflight via the email query parameter."}},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["email","domain","mailRoute","authentication","score","mailbox"],"properties":{"email":{"type":"string"},"score":{"type":"number"},"domain":{"type":"string"},"mailbox":{"type":"object"},"mailRoute":{"type":"object"},"authentication":{"type":"object"}}}}}}},"responseSchema":{"type":"json","example":{"email":"alice@example.com","score":95,"domain":"example.com","syntax":{"profile":"practical-ascii","accepted":true,"roleBased":false},"mailbox":{"smtpVerified":false,"deliverabilityClaimed":false},"mailRoute":{"hasMx":true,"nullMx":false,"verdict":"mail_route_configured"},"authentication":{"spf":{"status":"present"},"dmarc":{"policy":"reject","status":"present"}}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_FR7z6d5AfHZ4hO1eqT-M3","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates email address syntax and checks public DNS/mail infrastructure posture (MX, SPF, DMARC) without performing SMTP mailbox verification.","exampleAgentPrompt":"Can you preflight the email address alice@acmecorp.com and tell me whether the syntax is clean, whether the domain has MX records, and what SPF and DMARC policies are in place — without actually sending anything?","exampleUseCases":[{"title":"Pre-send deliverability check for newsletter signup","prompt":"Before we add bob@startup.io to our mailing list, can you check whether that email address has valid syntax, a configured mail route, and passing SPF and DMARC records — I want to know if it's safe to send to without actually pinging the mailbox."},{"title":"Fraud screening on new user registration","prompt":"A new user just signed up with the email noreply@suspiciousdomain.biz — can you run a preflight on it and tell me if it's a role-based address, whether the domain has MX records, and what its overall deliverability score looks like?"},{"title":"B2B outreach domain health audit","prompt":"I'm about to start cold outreach to leads at techcorp.com — can you check whether that domain has proper MX, SPF, and DMARC authentication set up so I know my emails won't bounce or get flagged as unauthenticated?"}],"resultDescription":"Returns a JSON object containing: a numeric deliverability score (0–100), parsed syntax profile (practical-ascii or similar) with accepted/roleBased flags, mail route assessment (hasMx, nullMx, verdict string), and DNS authentication posture for both SPF (present/missing status) and DMARC (policy type + status). Does not include SMTP-level mailbox existence verification.","failureModes":["Invalid or malformed email address input returns a syntax rejection with accepted:false","Domain with no DNS resolution may return hasMx:false and a degraded score","Rate limits or payment failures return 402 or 429 status codes","Transient DNS lookup failures may produce incomplete authentication fields","Extremely new domains may lack SPF/DMARC records, returning status:missing for those fields"],"whenToPreferThis":"Choose this endpoint when you need lightweight, pay-per-call email validation that goes beyond pure regex syntax checking to include real DNS infrastructure signals (MX, SPF, DMARC) but explicitly does not require or perform SMTP mailbox-level probing. Ideal for pre-send preflight checks, registration form validation, and lead scoring pipelines where SMTP probing is too slow, blocked, or legally inadvisable.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-18T01:19:30.619Z","isFirstParty":false,"canonicalSlug":"email-dns-preflight-3c6db3ee"}