# Mailcheck Email Validation & Deliverability

> Mailcheck Email Validation & Deliverability is a paid API for AI agents from mailcheck.x402tools.xyz, paid per call via x402, $0.03/call, status down (last checked 2026-10-13).

Validates an email address for deliverability, disposability, and risk using DNS/MX lookup, SMTP verification, and typo suggestions

## Facts

- Endpoint: POST https://mailcheck.x402tools.xyz/v1/validate?utm_source=zero.xyz
- Price: $0.03/call
- Payment: x402
- Status: down
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mailcheck-email-validation-deliverability-78c4733c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mndkJma0HYR-vVT9Zmw-m

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 mailcheck-email-validation-deliverability-78c4733c -d '<json body>'
```

Example prompt: Can you check whether jane.doe@gmial.com is a real, deliverable email address — including running the SMTP handshake — and let me know if there's a typo or if it's a disposable address?

## When to prefer this

Use this endpoint when you need a comprehensive, multi-layer email validation that goes beyond simple regex — specifically when you need SMTP-level deliverability confirmation, disposable domain detection, role-account flagging, and typo suggestions in a single pay-per-call API with no subscription required.

## Known failure modes

- Missing email parameter returns validation error
- Invalid email format may still be processed but returns syntax:false
- SMTP check may time out for slow mail servers, returning partial results
- Disposable domain database may not cover every known throwaway provider
- Catch-all domains always return mxAccepts:true regardless of real deliverability
- Payment failure via x402 prevents the call from completing

## How this service works

Validate any email for deliverability, disposability, and risk. DNS + SMTP verification, disposable domain detection, typo suggestions. Pay-per-call via x402 (USDC on Base).

## Output

Returns a JSON object with the original email, a numeric deliverability score (0–100), a boolean validity flag, per-check results (syntax, MX exists, MX accepts, catch-all, disposable, role account, free provider), the detected email provider name, and an optional corrected-spelling suggestion if a typo is detected.

## 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": [
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "email"
     ],
     "properties": {
      "email": {
       "type": "string",
       "description": "Email address to validate"
      },
      "checkSmtp": {
       "type": "boolean",
       "description": "Whether to perform SMTP handshake (default: true)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "email": {
       "type": "string"
      },
      "score": {
       "type": "number"
      },
      "valid": {
       "type": "boolean"
      },
      "checks": {
       "type": "object"
      },
      "provider": {
       "type": "string"
      },
      "suggestion": {
       "type": "string",
       "nullable": true
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "email": "jane.doe@gmail.com",
  "score": 92,
  "valid": true,
  "checks": {
   "syntax": true,
   "catchAll": false,
   "mxExists": true,
   "mxAccepts": true,
   "disposable": false,
   "roleAccount": false,
   "freeProvider": true
  },
  "provider": "Google",
  "suggestion": null
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mailcheck-email-validation-deliverability-78c4733c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mailcheck.x402tools.xyz](https://www.zero.xyz/host/mailcheck.x402tools.xyz/llms.txt)