# TrustSource Email Authentication Checker

> TrustSource Email Authentication Checker is a paid API for AI agents from api.trustsource.cc, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Checks a domain's email authentication posture (SPF, DMARC, DKIM, MX records) and returns an overall email trust score.

## Facts

- Endpoint: GET https://api.trustsource.cc/emailtrust
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/trustsource-email-authentication-checker-fbbe50c4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xkMspkIEXZVqeFYClOrZf

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 trustsource-email-authentication-checker-fbbe50c4
```

Example prompt: Can you check the email authentication setup for paypal.com — I want to know if they have SPF, DMARC, and DKIM configured and what their overall email trust score looks like?

## When to prefer this

Use this endpoint when you need a comprehensive, all-in-one assessment of a domain's email authentication configuration (SPF, DMARC, DKIM, MX) with a single API call. Prefer it over manual DNS lookups when you need a scored trust verdict rather than raw DNS record data, or when evaluating whether an inbound email sender domain is properly authenticated.

## Known failure modes

- Invalid or malformed domain/email input returns an error
- Domain does not exist in DNS — returns missing record statuses
- DNS lookup timeout for slow or non-responsive name servers
- Missing required 'domain' query parameter returns 400-level error
- Rate limiting or payment failure returns 402 or 429 response

## How this service works

Grade a domain's email-authentication posture (SPF, DKIM, DMARC, BIMI, MX) and tell an agent whether the sender can be spoofed. Returns an A–F grade, a `spoofable` flag, the parsed DMARC policy and SPF qualifier, and specific misconfiguration issues. Use to judge a sender domain before trusting an email, or to confirm your own outreach domain won't be silently rejected by Gmail/Yahoo/Microsoft's 2026 authentication rules.

## Output

Returns the domain's SPF record status, DMARC policy details, DKIM configuration, MX record presence, and an overall email trust score, giving a comprehensive picture of the domain's email authentication posture.

## 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": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "description": "Sender domain or email address to grade (e.g. example.com or user@example.com)."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/trustsource-email-authentication-checker-fbbe50c4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.trustsource.cc](https://www.zero.xyz/host/api.trustsource.cc/llms.txt)