# Lookproof Mail Provider Identifier

> Lookproof Mail Provider Identifier is a paid API for AI agents from api.lookproof.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-31).

Identifies the mail hosting provider and email sending services for a domain by analyzing its MX records and SPF include tree

## Facts

- Endpoint: GET https://api.lookproof.dev/v1/mail/provider?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/lookproof-mail-provider-identifier-64d554a5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Mbp9l_HGnDmwN4j_psw28

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 lookproof-mail-provider-identifier-64d554a5
```

Example prompt: Can you tell me which mail provider and email sending services are used by acme.com — I want to know who hosts their mailboxes and whether any third-party services are still authorized in their SPF record?

## When to prefer this

Use this endpoint when you need to definitively name the mail provider(s) behind a domain rather than just retrieve raw DNS records. It is ideal when an agent needs to classify email infrastructure at scale, audit SPF authorization after a provider migration, or identify whether a domain uses Google Workspace, Microsoft 365, Proofpoint, Mimecast, or another named provider — without having to manually parse and match MX hostnames or SPF include chains yourself.

## Known failure modes

- Domain not found or no MX records — returns empty or null provider list
- Invalid domain format — returns validation error
- Domain has no SPF record — SPF-based sending services not enumerated
- Unrecognized mail infrastructure — returns raw MX/SPF data without a named provider match
- Network timeout resolving DNS — returns error response
- Rate limit exceeded — returns 429 or payment-required error

## How this service works

Check SPF, DMARC, DKIM, MTA-STS, DNSSEC and more, with results that explain what was found and why. Free browser checks and a pay-per-request API with x402.

## Output

Returns a structured list of identified mail providers for the domain, including the mailbox provider behind the primary MX, any inbound gateways, and sending services found in the SPF include tree. Each match includes the provider name and the MX or SPF evidence that triggered the match, drawn from a fixed versioned reference list.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "title": "DomainInput",
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "title": "Domain",
       "examples": [
        "example.com"
       ],
       "maxLength": 1024,
       "minLength": 1
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/lookproof-mail-provider-identifier-64d554a5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.lookproof.dev](https://www.zero.xyz/host/api.lookproof.dev/llms.txt)