{"uid":"cap_vxTmeGOqpd_K9ube-UPwT","slug":"dns-txt-record-lookup-for-smtp-subdomain-0d088540","name":"DNS TXT Record Lookup for smtp Subdomain","description":"TXT record of smtp.<domain>: looks up the smtp host under the domain you give (TXT via Cloudflare DoH) and reports whether it exists, its records and TTL. Quick existence check for common hosts like smtp without enumerating subdomains. $0.01 per lookup.","url":"https://dns.intel.rallylive.ca/dns/host/smtp/txt?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$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"],"type":"string"},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_dkICCBjOgL0ISIEn1uEnq","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Looks up TXT DNS records for the smtp.<domain> subdomain via Cloudflare DNS-over-HTTPS and returns existence status, records, and TTL","exampleAgentPrompt":"Can you check if there's a TXT record configured for the smtp subdomain of example.com — I want to know if smtp.example.com exists in DNS and what its records and TTL are?","exampleUseCases":[{"title":"Verify SMTP subdomain DNS presence","prompt":"Check whether smtp.acmecorp.com has any TXT records in DNS — I need to know if that subdomain exists and what records are there before setting up our mail relay."},{"title":"Email infrastructure audit","prompt":"I'm auditing the mail configuration for clientdomain.io — can you look up the TXT records on its smtp subdomain and tell me the TTL and what you find?"},{"title":"Detect misconfigured SMTP host","prompt":"Does smtp.startupco.net have a TXT record in DNS? I'm trying to figure out if someone already set up an smtp host there or if the subdomain is missing entirely."}],"resultDescription":"Returns whether the smtp.<domain> subdomain has TXT records, the content of those records if they exist, the TTL, and the DNS response code (e.g. NOERROR, NXDOMAIN). Answered by Cloudflare DNS-over-HTTPS.","failureModes":["Domain does not exist — returns NXDOMAIN with no records","smtp subdomain has no TXT records — returns empty record set","Malformed domain input — may return error or empty result","Cloudflare DoH unavailable — request may time out","Rate limiting or payment failure — 402 response if funds not available"],"whenToPreferThis":"Use this endpoint when you need a quick, targeted check on whether the smtp host under a given domain has TXT DNS records, without enumerating all subdomains. Prefer this over general DNS lookups when specifically investigating email-related subdomain configuration or verifying SMTP infrastructure presence at low cost ($0.01 per lookup).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T18:55:48.367Z","isFirstParty":false,"canonicalSlug":"dns-txt-record-lookup-for-smtp-subdomain-0d088540"}