# AgentTools Email Validator (Syntax + MX Check)

> AgentTools Email Validator (Syntax + MX Check) is a paid API for AI agents from agenttools-hub.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Validates an email address with two-layer checking: strict RFC-style syntax validation followed by a live DNS MX lookup to confirm the domain actually accepts mail.

## Facts

- Endpoint: GET https://agenttools-hub.vercel.app/api/v1/dev/email-validator?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agenttools-email-validator-syntax-mx-check-31a097e0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_605IVOVLS6apUs-7tpXlL

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 agenttools-email-validator-syntax-mx-check-31a097e0
```

Example prompt: Can you check if the email address john.doe@example-company.com is actually valid — both the format and whether that domain has real mail servers set up?

## When to prefer this

Choose this endpoint when you need to go beyond basic regex validation and confirm a domain actually runs mail infrastructure — ideal for sign-up flows, lead qualification, mailing list hygiene, or any scenario where sending to a bad address has a cost. Prefer this over pure client-side regex checks or single-layer syntax validators when deliverability confidence matters.

## Known failure modes

- Domain exists but has no MX records — email is syntactically valid but undeliverable
- DNS lookup timeout or failure returns an indeterminate result for MX check
- Malformed email input causes immediate syntax failure without MX check
- Valid MX records exist but specific mailbox may still not exist (not checked at this layer)
- Temporary DNS propagation issues may cause false negatives on newly registered domains

## How this service works

Validate an email address in two layers: strict RFC-style syntax, then a live DNS MX lookup on the domain to confirm the recipient actually runs mail servers. Catches the typos and fake domains that pure regex misses. Use this when an agent needs to syntax + live MX check — can this address receive mail?.

## Output

Returns a two-layer validation result: whether the email passes RFC-style syntax rules, and whether the email's domain has live DNS MX records confirming it can receive mail. Catches typos and fake/non-existent domains that regex alone would miss.

## 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"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agenttools-email-validator-syntax-mx-check-31a097e0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agenttools-hub.vercel.app](https://www.zero.xyz/host/agenttools-hub.vercel.app/llms.txt)