{"uid":"cap_VPTGkymhIDfdVOEPRnyl_","slug":"lookproof-mta-sts-policy-parser-da31cf89","name":"Lookproof MTA-STS Policy Parser","description":"Check SPF, DMARC, DKIM, MTA-STS, DNSSEC and more, with results that explain what was found and why. Free browser checks and a pay-per-request API with x402.","url":"https://api.lookproof.dev/v1/mail/mta-sts-parse?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"policy":{"type":"string","title":"Policy","maxLength":8192,"minLength":1}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_KXLpCqN0r1_7MyHkJmXwZ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Parses and validates a pasted MTA-STS policy file (RFC 8461) offline, checking version, mode, MX patterns, max_age, and flagging non-conforming lines or risky settings.","exampleAgentPrompt":"Can you parse this MTA-STS policy for me and tell me if it's valid — check the version, mode, MX patterns, and max_age, and flag anything that looks wrong: 'version: STSv1\\nmode: enforce\\nmx: mail.example.com\\nmax_age: 86400'?","exampleUseCases":[{"title":"Pre-publish MTA-STS policy check","prompt":"Before I publish this MTA-STS policy, can you parse it and tell me if the version, mode, MX entries, and max_age all look correct, and flag any lines that won't parse? Here's the policy: 'version: STSv1\\nmode: enforce\\nmx: mail.example.com\\nmx: mail2.example.com\\nmax_age: 604800'"},{"title":"Catching testing-mode risk before go-live","prompt":"I have an MTA-STS policy I'm about to deploy — can you check if it's still in testing mode or has a max_age that's too short? Policy text: 'version: STSv1\\nmode: testing\\nmx: smtp.mycompany.com\\nmax_age: 300'"},{"title":"Debugging a rejected MTA-STS policy","prompt":"My MTA-STS policy might have a syntax error causing sending servers to reject it — can you parse it line by line and tell me which lines don't conform to RFC 8461? Here's what I have: 'version: STSv1\\nmode: enforce\\nmx: *.mail.example.org\\nmax_age: 31557600\\nbadline: foo'"}],"resultDescription":"Returns the parsed fields of the MTA-STS policy: version string, mode (enforce/testing/none), list of MX host patterns, max_age integer, any lines that failed to parse, and warnings if the mode is 'testing' or 'none' or if max_age is unusually short. All processing is done offline without making DNS queries.","failureModes":["Policy text is empty or exceeds 8192 characters — request rejected","Policy has no parseable fields at all — returns empty parsed output with unparsed lines listed","Network error reaching api.lookproof.dev — standard HTTP 5xx response","Malformed JSON request body — HTTP 400 bad request"],"whenToPreferThis":"Use this endpoint when an agent or developer needs to validate or preview an MTA-STS policy file before publishing it to a web server, without making any DNS or HTTP requests to the live domain. Prefer it over live MTA-STS lookup tools when the policy isn't yet deployed, when you want offline/deterministic validation, or when you're generating or editing policy content programmatically.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:40:48.328Z","isFirstParty":false,"canonicalSlug":"lookproof-mta-sts-policy-parser-da31cf89"}