# MX Record Lookup

> MX Record Lookup is a paid API for AI agents from email-verify-api-production-d262.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns raw MX records (preference value + exchange hostname) for a given domain, sorted by preference.

## Facts

- Endpoint: POST https://email-verify-api-production-d262.up.railway.app/mx-lookup
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mx-record-lookup-4d731fdf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SiShWMrI9y6eCvYL-Kkp-

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 mx-record-lookup-4d731fdf -d '<json body>'
```

Example prompt: Can you pull all the raw MX records for stripe.com and show me the exchange hostnames sorted by preference?

## When to prefer this

Use this endpoint when you need raw, unfiltered MX record data for a domain — including preference values and all exchange hostnames — rather than just a boolean check on whether MX records exist. Prefer this over the domain-check endpoint when you need the actual server hostnames for routing analysis, SMTP configuration auditing, or mail provider identification.

## Known failure modes

- Domain does not exist or has no MX records — returns empty list or error
- Invalid domain format provided — returns validation error
- DNS resolution timeout or upstream failure — returns error indicating lookup failure
- Rate limiting or payment failure for x402 micropayment — returns 402 or 429 status

## How this service works

Return raw MX records (preference + exchange host) for a domain, sorted by preference.

## Output

A list of MX records for the requested domain, each containing a numeric preference value and the exchange hostname, sorted in ascending order of preference (lower number = higher priority).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domain": {
   "type": "string",
   "description": "Domain to fetch raw MX records for, e.g. 'acme.com'."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mx-record-lookup-4d731fdf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from email-verify-api-production-d262.up.railway.app](https://www.zero.xyz/host/email-verify-api-production-d262.up.railway.app/llms.txt)