# Bulk Email Validation API (x402-gateway.blackwoodstate8.workers.dev) > Bulk Email Validation API (x402-gateway.blackwoodstate8.workers.dev) is a paid API for AI agents from x402-gateway.blackwoodstate8.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-23). Validates up to 20 email addresses per call, checking syntax, MX records, disposable/free/role flags, SPF, DMARC, and returning a verdict for each address. ## Facts - Endpoint: POST https://x402-gateway.blackwoodstate8.workers.dev/v1/email-batch?utm_source=zero.xyz - Price: $0.02/call - Payment: x402 - Status: unknown - Last checked: 2026-10-23 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/bulk-email-validation-api-x402-gateway-blackwoodstate8-workers-dev-30a99863 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3t68B__6Yl0UbqCyiWpPC Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability bulk-email-validation-api-x402-gateway-blackwoodstate8-workers-dev-30a99863 -d '' ``` Example prompt: Before I import these emails into my CRM, can you batch-verify them for me — check syntax, whether the domains accept mail, and flag any disposable or role-based addresses: alice@example.com, info@widgets.io, bob@tempmail.com, jane@gmail.com, support@acme.org? ## When to prefer this Use this endpoint when you need to validate between 2 and 20 email addresses in a single call and want comprehensive checks including syntax, DNS/MX, disposable detection, role-account flagging, SPF and DMARC analysis. Prefer this over single-address email-check endpoints when working with lists; it is more cost-efficient per address at scale. Do not use this if you need SMTP probing to confirm a specific mailbox exists, if you need to send email, or if you only have one address (a cheaper single-check endpoint may be preferable). ## Known failure modes - More than 20 emails submitted — returns validation error - Invalid email string format in array — individual entry marked syntax invalid - Domain with no MX records — mx array empty, acceptsMail false - DMARC/SPF lookup timeout — fields may be null - Network timeout for DNS lookups within the 2500ms p95 window - Payment not attached or insufficient — x402 payment required error ## How this service works Use when you need bulk email validation, email list verification or to verify email lists before a send or import. Do not use for one address (email-check is cheaper), proving a mailbox exists (no SMTP probe) or sending email. Returns JSON checking up to 20 email addresses in one call: syntax, MX records, disposable, free and role flags, SPF, DMARC and a verdict each, plus counts by verdict for 0.02 USDC per call. Typical response time 2500 ms (p95). Category: Data. ## Output Returns a JSON object with a results array (one entry per email address) containing: normalized email, syntax validity, domain, MX records, disposable/free provider/role account flags, domain existence, SPF and DMARC records and policy, a per-address verdict, reasons for the verdict, and whether SMTP was checked. Also includes aggregate summary counts by verdict and the number of unique domains checked. ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method", "bodyType", "body" ], "properties": { "body": { "type": "object", "required": [ "emails" ], "properties": { "emails": { "type": "array", "items": { "type": "string", "maxLength": 320 }, "maxItems": 20, "minItems": 1, "description": "Email addresses to check, 1 to 20, e.g. [\"jane@example.com\", \"info@ietf.org\"]" } } }, "type": { "type": "string", "const": "http" }, "method": { "enum": [ "POST" ], "type": "string" }, "bodyType": { "enum": [ "json", "form-data", "text" ], "type": "string" } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "required": [ "count", "domains", "summary", "results" ], "properties": { "next": { "type": "object", "required": [ "service", "tool", "method", "url", "useWhen", "sample" ], "properties": { "url": { "type": "string", "description": "Paid route of the next call" }, "tool": { "type": "string", "description": "MCP tool name of the same call" }, "method": { "enum": [ "GET", "POST" ], "type": "string" }, "sample": { "type": "string", "description": "Free fixed sample of the whole family" }, "service": { "type": "string", "description": "Service id of the suggested next paid call" }, "useWhen": { "type": "string", "description": "When the next call is the right one" } }, "description": "Suggested next paid call in the same family (call it in a loop when the task continues)", "additionalProperties": false }, "count": { "type": "number" }, "domains": { "type": "number" }, "results": { "type": "array", "items": { "type": … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "count": 4, "domains": 3, "results": [ { "mx": [ { "host": "mx.ietf.org", "priority": 0 } ], "spf": "v=spf1 ip4:166.84.6.31 ip4:166.84.7.238 ip6:2602:f977:800:f7f6::/64 ip4:166.84.7.34 ip6:2602:f977:800::e276:63ff:fe66:3400 include:_spf.google.com include:spf.hostedrt.com ~all", "dmarc": "v=DMARC1; p=none; rua=mailto:dmarc_agg@vali.email,mailto:dmarc-report@ietf.org", "email": "postmaster@ietf.org", "domain": "ietf.org", "reasons": [ "role_account" ], "verdict": "deliverable_domain", "disposable": false, "normalized": "postmaster@ietf.org", "acceptsMail": true, "dmarcPolicy": "none", "roleAccount": true, "smtpChecked": false, "syntaxValid": true, "domainExists": true, "freeProvider": false }, { "mx": [ { "host": "mail.mailinator.com", "priority": 1 }, { "host": "mail2.mailinator.com", "priority": 1 } ], "spf": "v=spf1 -all", "dmarc": "v=DMARC1;p=reject;sp=reject;aspf=s;pct=100", "email": "test@mailinator.com", "domain": "mailinator.com", "reasons": [ "disposable" ], "verdict": "risky", "disposable": true, "normalized": "test@mailinator.com", "acceptsMail": true, "dmarcPolicy": "reject", "roleAccount": false, "smtpChecked": false, "syntaxValid": true, "domainExists": true, "freeProvider": false }, { "mx": [], "spf": "v=spf1 -all", "dmarc": "v=DMARC1;p=reject;sp=reject;adkim=s;aspf=s", "email": "info@example.com", "domain": "example.com", "reasons": [ "null_mx", "role_account" ], "verdict": "undeliverable", "disposable": false, "normalized": "info@example.com", "acceptsMail": false, "dmarcPolicy": "reject", "roleAccount": true, "smtpChecked": false, "syntaxValid": true, "domainExists": true, "freeProvider": false }, { "mx": [], "spf": null, "dmarc": null, "email": "not-an-email", "domain": null, "reasons": [ "syntax" ], "verdict": "invalid", "disposable": false, "normalized": null, "acceptsMail": false, "dmarcPolicy": null, "roleAccount": false, "smtpChecked": false, "syntaxValid": false, "domainExists": null, "freeProvider": false } ], "summary": { "risky": 1, "invalid": 1, "unknown": 0, "undeliverable": 1, "deli … (truncated) ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bulk-email-validation-api-x402-gateway-blackwoodstate8-workers-dev-30a99863/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from x402-gateway.blackwoodstate8.workers.dev](https://www.zero.xyz/host/x402-gateway.blackwoodstate8.workers.dev/llms.txt)