# fittings Email Deliverability Validator

> fittings Email Deliverability Validator is a paid API for AI agents from fittings.sh, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-11).

Validates a single email address by checking RFC 5322 syntax, resolving live MX records, and flagging disposable/temporary email providers in one call.

## Facts

- Endpoint: GET https://fittings.sh/v1/email/deliverability?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fittings-email-deliverability-validator-a8ae47d5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UignAPJw1qJAThGinaIQy

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 fittings-email-deliverability-validator-a8ae47d5
```

Example prompt: Can you check whether john.doe@tempmail.io is a real, deliverable email address — specifically verify the syntax is correct, that the domain has working mail servers, and whether it's from a disposable email provider?

## When to prefer this

Choose this endpoint when you need a single-call, three-in-one email check combining syntax validation, live DNS MX resolution, and disposable-provider detection — ideal for real-time user registration flows, lead qualification, or pre-send list hygiene where speed and cost matter. Prefer it over heavier email verification services when you don't need SMTP handshake verification or full inbox existence checks.

## Known failure modes

- Email address exceeds 320 characters — request rejected
- Malformed input with no email query parameter — validation error returned
- DNS resolution timeout for obscure or newly-registered domains — MX check may be inconclusive
- Disposable provider list may not cover very new or niche throwaway services
- Valid syntax with no MX records returns deliverable: false but does not indicate a typo

## How this service works

RFC 5322 syntax check, live MX resolution and a disposable-provider check for one email address, in a single call.

## Output

Returns a structured result indicating whether the email passes RFC 5322 syntax validation, whether live MX records were found for the domain via DNS resolution, and whether the domain belongs to a known disposable or temporary email provider.

## 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": "Up to 320 characters"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fittings-email-deliverability-validator-a8ae47d5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fittings.sh](https://www.zero.xyz/host/fittings.sh/llms.txt)