# Null MX: A Domain That Accepts No Mail

The MX record of example.com: a null MX (0 .), the way a domain says it accepts no mail.

Source: https://docs.deepinfo.com/reference/lookup/dns/examples/null-mx/

Last updated: 2026-09-24

---
`GET https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX`

The MX record of example.com: a null MX (0 .), the way a domain says it accepts no mail.

Example 3 of 3 in **Special Answers** · [DNS Lookup Examples](/reference/lookup/dns/examples/) · endpoint: [DNS](/reference/lookup/dns/)

Tags: `param` `domain` · `param` `type` · `value` `example.com` · `value` `MX`

Asks for the `MX` records of `example.com`.

The single record `0 .` (priority 0, an empty host) is a "null MX" (RFC 7505): the domain declares that it accepts no e-mail. `raw` shows the record as `MX 0 .`, and `values` as `0 ` with the dot removed.

## Request

| Parameter | In | Value |
|---|---|---|
| `domain` | query | `example.com` |
| `type` | query | `MX` |

```bash
curl 'https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX' \
  -H 'apikey: YOUR_API_KEY' \
  -H 'Accept: application/json'
```

## Response

### 200 · OK

`Content-Type: application/json` · `ratelimit-limit: 100000` · `ratelimit-remaining: 99981` · `ratelimit-reset: 25` · `x-ratelimit-limit-minute: 100000` · `x-ratelimit-remaining-minute: 99981` · `deepinfo-request-id: 5f0c6a8e-1b2d-4c3e-9f4a-7b8c9d0e1f2a`

```json
{
  "fqdn": "example.com",
  "requested_types": [
    "MX"
  ],
  "responses": [
    {
      "type": "MX",
      "conn_status": "success",
      "rcode": "NOERROR",
      "raw": "example.com. 300 IN MX 0 .",
      "values": [
        "0 "
      ],
      "server": "8.8.8.8"
    }
  ],
  "servers": [
    "8.8.8.8"
  ],
  "check_date": "2026-09-24T07:48:35Z"
}
```

## Related Examples

- [MX Records: Mail Servers](/reference/lookup/dns/examples/type-mx/)
- [A Domain That Is Not Registered](/reference/lookup/dns/examples/unregistered-domain/)
- [A Name Without Records of the Requested Type](/reference/lookup/dns/examples/no-records/)
- [A Host Name Behind a CNAME](/reference/lookup/dns/examples/www-a-cname/)
- [Five Types at Once](/reference/lookup/dns/examples/five-types/)
- [Mail Setup: MX and TXT](/reference/lookup/dns/examples/types-mx-txt/)