# Hunter Email Verifier

> Hunter Email Verifier is a paid API for AI agents from StableEnrich at stableenrich.dev, paid per call via MPP or x402, $0.03/call, status unknown (last checked 2026-10-10, last successful call 2026-06-25).

Verifies the deliverability of an email address by checking SMTP, MX records, disposability, and other signals to produce a validity status and confidence score

## Facts

- Endpoint: POST https://stableenrich.dev/api/hunter/email-verifier?utm_source=zero.xyz
- Price: $0.03/call
- Payment: MPP, x402
- Status: unknown
- Last checked: 2026-10-10
- Last successful call: 2026-06-25
- Success rate: 90% of calls made through Zero
- Activations on Zero: 21
- Provider: StableEnrich
- Docs: https://stableenrich.dev
- Website: https://stableenrich.dev
- Tags: apollo, exa, firecrawl, google-maps, linkedin, reddit, enrichment, research, data, search, social
- Canonical page: https://www.zero.xyz/c/stableenrich-email-verifier-7576dcf9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SftQaWU_RZqVzeppGfnJ0

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 stableenrich-email-verifier-7576dcf9 -d '<json body>'
```

Example prompt: Can you verify whether john.smith@acme.com is a real, deliverable email address — check if it's disposable, has valid MX records, and give me a deliverability score?

## When to prefer this

Use this endpoint when you need to verify individual email addresses before outreach campaigns, user registration, or data enrichment workflows. Prefer this over format-only validators when you need real SMTP and MX-level verification. Choose this when you need Hunter's additional signal of web-sourced sightings of the email address, or when you need disposable/webmail/gibberish detection beyond basic format checks.

## Known failure modes

- Invalid email format returns validation error before API call
- Unknown or unresolvable domain returns status 'unknown' with low score
- Disposable/temporary email services return status 'disposable'
- SMTP server unreachable returns smtp_server: false and smtp_check: false
- Accept-all domains return status 'accept_all' — cannot confirm individual address
- Rate limit or payment failure returns 402 or 429 error

## How this service works

Hunter - Verify email deliverability. Fast and cached verifications return the final result immediately; Hunter pending responses return a job id to poll with SIWX.

## Output

Returns a structured object with: a status enum (valid/invalid/accept_all/webmail/disposable/unknown), a numeric deliverability score (0–1), and boolean flags for regexp match, gibberish detection, disposable address, webmail provider, MX records existence, SMTP server reachability, SMTP deliverability check, accept-all domain, and blocked status. Also includes an array of web sources where the email was previously seen.

## Example request

```json
{
 "email": "zero-qa@agentmail.to"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "email"
 ],
 "properties": {
  "email": {
   "type": "string",
   "format": "email",
   "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$",
   "description": "Email address to verify"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "anyOf": [
  {
   "type": "object",
   "required": [
    "status",
    "score",
    "email",
    "regexp",
    "gibberish",
    "disposable",
    "webmail",
    "mx_records",
    "smtp_server",
    "smtp_check",
    "accept_all",
    "block",
    "sources"
   ],
   "properties": {
    "block": {
     "type": "boolean"
    },
    "email": {
     "type": "string"
    },
    "score": {
     "type": "number"
    },
    "regexp": {
     "type": "boolean"
    },
    "status": {
     "enum": [
      "valid",
      "invalid",
      "accept_all",
      "webmail",
      "disposable",
      "unknown"
     ],
     "type": "string"
    },
    "sources": {
     "type": "array",
     "items": {
      "type": "object",
      "required": [
       "domain",
       "uri",
       "extracted_on",
       "last_seen_on",
       "still_on_page"
      ],
      "properties": {
       "uri": {
        "type": "string"
       },
       "domain": {
        "type": "string"
       },
       "extracted_on": {
        "type": "string"
       },
       "last_seen_on": {
        "type": "string"
       },
       "still_on_page": {
        "type": "boolean"
       }
      },
      "additionalProperties": false
     },
     "default": []
    },
    "webmail": {
     "type": "boolean"
    },
    "gibberish": {
     "type": "boolean"
    },
    "accept_all": {
     "type": "boolean"
    },
    "disposable": {
     "type": "boolean"
    },
    "mx_records": {
     "type": "boolean"
    },
    "smtp_check": {
     "type": "boolean"
    },
    "smtp_server": {
     "type": "boolean"
    }
   },
   "additionalProperties": false
  },
  {
   "type": "object",
   "required": [
    "jobId",
    "status",
    "pollUrl",
    "retryAfterSeconds"
   ],
   "properties": {
    "jobId": {
     "type": "string",
     "description": "StableEnrich job id for the pending verification"
    },
    "status": {
     "type": "string",
     "const": "pending"
    },
    "pollUrl": {
     "type": "string",
     "format": "uri",
     "description": "SIWX-authenticated URL to poll"
    },
    "retryAfterSeconds": {
     "type": "integer",
     "maximum": 9007199254740991,
     "exclusiveMinimum": 0
    }
   },
   "additionalProperties": false
  }
 ]
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stableenrich-email-verifier-7576dcf9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stableenrich.dev](https://www.zero.xyz/host/stableenrich.dev/llms.txt)