# Factline Email Verification

> Factline Email Verification is a paid API for AI agents from factline.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-11).

Validates and verifies an email address for deliverability using DNS/MX checks, disposable domain detection, typo suggestions, and syntax validation, returning a single verdict of deliverable, risky, or undeliverable.

## Facts

- Endpoint: GET https://factline.dev/v1/email/verify?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/factline-email-verification-e5a1d350
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_twePyJVMrLSAO9Cy336dL

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 factline-email-verification-e5a1d350
```

Example prompt: Can you verify whether jan.jansen@gmial.com is a real, deliverable email address — check if it's disposable, has valid DNS mail routing, and flag any typos?

## When to prefer this

Choose this endpoint when you need a fast, single-verdict email quality check that combines RFC syntax validation, live DNS/MX routing, disposable domain screening (9,000+ domains), typo detection, and role-address flagging in one call — especially for signup flows, CRM enrichment, or outreach list hygiene where you need more than basic regex but don't require SMTP mailbox probing.

## Known failure modes

- Missing or malformed email parameter returns an error
- Domains with no DNS response may timeout or return undeliverable
- No SMTP mailbox probe — confirms domain can receive mail but not that the specific mailbox exists
- Newly registered disposable domains not yet in the blocklist may pass as deliverable
- Rare TLDs or private domains may yield incomplete MX information

## How this service works

API and MCP servers that let AI agents and apps check people, companies, Dutch addresses and cars against official records: sanctions and PEP lists, 10 company registers, Dutch property, rent and RDW vehicle data. From $0.001 per call.

## Output

A JSON object containing: overall verdict (deliverable, deliverable_role, risky, or undeliverable), syntax validity, mail routing details (MX records, null MX, implicit MX, accepts_mail, domain_exists), disposable flag, role account flag, free provider flag, domain security (SPF, DMARC policy), typo suggestion if applicable, list of human-readable reasons, and the data source used.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "email"
     ],
     "properties": {
      "email": {
       "type": "string",
       "description": "Email address to verify, e.g. jan.jansen@example.nl"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "email": "jan.jansen@gmial.com",
  "domain": "gmial.com",
  "source": "DNS via Cloudflare 1.1.1.1 (DNS-over-HTTPS); disposable-email-domains (CC0)",
  "explain": {
   "limits": "No SMTP mailbox probe: this confirms the domain can receive mail, not that this exact mailbox exists.",
   "verdict": "deliverable: domain receives mail and nothing suspicious; deliverable_role: same but a shared inbox; risky: disposable domain or likely typo; undeliverable: bad syntax or the domain cannot receive mail.",
   "disposable_list": "disposable-email-domains blocklist (CC0), 2026-10-07"
  },
  "reasons": [
   "disposable (throwaway) email domain",
   "possible typo of gmail.com"
  ],
  "verdict": "risky",
  "disposable": true,
  "suggestion": "jan.jansen@gmail.com",
  "mail_routing": {
   "mx": [],
   "null_mx": false,
   "implicit_mx": true,
   "accepts_mail": true,
   "domain_exists": true
  },
  "role_account": false,
  "syntax_valid": true,
  "free_provider": false,
  "domain_security": {
   "spf": false,
   "dmarc_policy": null
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/factline-email-verification-e5a1d350/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from factline.dev](https://www.zero.xyz/host/factline.dev/llms.txt)