{"uid":"cap_Uj2BT9uIJur06ecs7ke6u","slug":"agent-email-check-single-address-8bd14886","name":"Agent Email Check (Single Address)","description":"DNS and list based verification. Never claims that a mailbox exists without evidence: without an SMTP probe the verdict for a routable address is \"unknown\", not \"valid\".","url":"https://mail.halowerk.com/email","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"email":{"type":"string","description":"The email address to check."},"smtp_check":{"type":"boolean","default":false,"description":"Ask for an optional SMTP probe. Off by default, heavily throttled, one attempt per target and never retried. Without it the verdict of a routable address stays \"unknown\"."}}},"responseSchema":null,"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_jF4sdLysATSdgyEcPDm1s","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":"Verifies a single email address using DNS and blocklist checks, with an optional SMTP probe, returning a conservative verdict that distinguishes unknown-but-routable from confirmed-valid.","exampleAgentPrompt":"Can you verify whether john.doe@example.com is a real, deliverable email address — go ahead and run the SMTP probe too so we get a definitive answer rather than just 'unknown'.","exampleUseCases":[{"title":"Pre-send lead list hygiene","prompt":"Before we send our outreach campaign, check whether sarah.jones@acmecorp.com is actually deliverable — use the SMTP probe so we know for sure it's not just a routable domain."},{"title":"Signup form validation","prompt":"A user just registered with the email mike.smith@freemail.io — can you verify it's a real address? Skip the SMTP probe for now, DNS check is fine."},{"title":"CRM data quality audit","prompt":"We have a new contact with the email cto@startup.xyz — run a full check including the SMTP probe and tell me whether that mailbox actually exists before I add them to our pipeline."}],"resultDescription":"A JSON verdict indicating whether the email address is valid, invalid, or unknown (routable domain but mailbox unconfirmed without SMTP probe). Includes DNS resolution status, domain routability, any blocklist signals, and — if smtp_check was requested — the result of a one-time SMTP connection attempt to confirm mailbox existence.","failureModes":["Email address is malformed — returns invalid immediately without DNS lookup","Domain is routable but smtp_check was false — verdict is 'unknown', not 'valid'","SMTP probe is rate-limited or throttled — only one attempt per target, never retried, may return inconclusive","Target mail server blocks or graylists SMTP probes — probe result may be unreliable","Domain does not exist or has no MX records — returns unroutable/invalid"],"whenToPreferThis":"Choose this endpoint when you need a conservative, non-spammy email check that distinguishes between 'definitely invalid', 'probably routable but unconfirmed', and 'confirmed valid via SMTP'. It is especially useful when false positives (treating bad emails as good) are costly — e.g. CRM hygiene, outreach campaigns, or signup validation — and when you want honest uncertainty rather than an optimistic guess. Prefer the optional SMTP probe when a definitive answer is needed and the target domain is not known to block probes.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T12:36:27.533Z","isFirstParty":false}