{"uid":"cap_a11MRewR91IOiK4IeXopP","slug":"email-syntax-checker-rfc-5322-no-dns-e94b64a3","name":"Email Syntax Checker (RFC 5322, No DNS)","description":"Fast email syntax check (no DNS): validates local part and domain shape per RFC 5322 practical rules, flags leading/trailing/double dots, invalid characters, missing TLD and length limits. Sub-millisecond input validation for forms and agents. $0.01 per address.","url":"https://intel.rallylive.ca/email/syntax","method":"GET","headers":{},"bodySchema":{"type":"object","$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_tV9IzbsqWNhZtrzOLN0Hg","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":"Validates email address syntax against RFC 5322 rules — checking local part, domain shape, dots, invalid characters, missing TLD, and length limits — without performing any DNS lookup.","exampleAgentPrompt":"Can you check whether 'john..doe@example' is a valid email address format — just syntax, no DNS lookup needed?","exampleUseCases":[{"title":"Form input validation before submission","prompt":"Before submitting this signup form, check if the email address 'user@.example.com' is correctly formatted — I just want a syntax check, no need to ping DNS."},{"title":"Bulk pre-filter of scraped contacts","prompt":"I have an email address 'first.last@domain' that was scraped from a webpage — can you run a quick RFC 5322 syntax check to see if it's even valid before I add it to my list?"},{"title":"Catching typos in user-entered email","prompt":"A user just typed 'alice@exam..ple.co' into our registration form — does this pass basic email syntax validation, and if not, what's wrong with it?"}],"resultDescription":"Returns a syntactic validity verdict for the submitted email address along with specific flags for any rule violations found, such as leading/trailing/double dots, invalid characters in the local part or domain, missing TLD, or violations of length limits — all evaluated purely against RFC 5322 practical rules with no DNS resolution.","failureModes":["Missing email address parameter returns an error","Malformed query string may result in a 400 bad request","Payment not included or insufficient USDC results in a 402 Payment Required response","Edge-case RFC ambiguities (e.g. quoted local parts) may not be fully handled"],"whenToPreferThis":"Choose this endpoint when you need instant, sub-millisecond email format validation with no network dependency on DNS — ideal for real-time form validation, pre-filtering contact lists before DNS/SMTP checks, or agent pipelines where speed and offline-safe operation matter. Prefer it over MX-check or SMTP-verify endpoints when you only need structural correctness and cannot afford DNS latency or want to avoid external lookups.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T13:13:19.658Z","isFirstParty":false}