MX Records

What It Does

Queries MX records, identifies the email provider and security gateways, and surfaces three classes of misconfiguration as `sanity_flags`: MX hostnames that resolve via CNAME (a violation of RFC 5321 §5.1 that breaks delivery on strict resolvers), MX hostnames that resolve to private/reserved IPs (mail will never reach them), and lame mail delegation (MX with no A or AAAA at all). Detects Null MX (RFC 7505) — the explicit "this domain does not accept mail" signal. Enriches each MX IP with its ASN and country code via Team Cymru, surfaces unique-ASN and unique-country counts for diversity assessment, and returns a `linked_endpoints` hint for callers who want full SPF/DMARC/MX-Health analysis.

Why It's Useful

The sanity flags catch the three failure modes responsible for most "why isn't email arriving?" tickets — RFC 5321 forbids MX→CNAME, RFC 1918 IPs in MX records mean mail never leaves, and lame MX is invisible to plain `dig`. ASN + country enrichment gives M&A due diligence and fraud teams a clear "your MX moved to AS in another country" anomaly signal without writing the lookup themselves. Provider detection identifies the security gateways (Proofpoint, Mimecast, Barracuda) and downstream providers in the mail path so callers understand the defense stack.

Use Cases

Parameters

Response Fields

Code Examples

curl "https://api.edgedns.dev/v1/dns/mx" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d "domain=google.com"

const response = await fetch(
  'https://api.edgedns.dev/v1/dns/mx?domain=google.com',
  {
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY'
    }
  }
);

const data = await response.json();
console.log(data);

import requests

response = requests.get(
    'https://api.edgedns.dev/v1/dns/mx',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    params={
    'domain': 'google.com'
    }
)

data = response.json()
print(data)

Related Endpoints

External References

Learn more about the standards and protocols behind this endpoint.