# Lookproof MTA-STS Policy Parser

> Lookproof MTA-STS Policy Parser is a paid API for AI agents from api.lookproof.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Parses and validates a pasted MTA-STS policy file (RFC 8461) offline, checking version, mode, MX patterns, max_age, and flagging non-conforming lines or risky settings.

## Facts

- Endpoint: POST https://api.lookproof.dev/v1/mail/mta-sts-parse?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/lookproof-mta-sts-policy-parser-da31cf89
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VPTGkymhIDfdVOEPRnyl_

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-mta-sts-policy-parser-da31cf89 -d '<json body>'
```

Example prompt: Can you parse this MTA-STS policy for me and tell me if it's valid — check the version, mode, MX patterns, and max_age, and flag anything that looks wrong: 'version: STSv1\nmode: enforce\nmx: mail.example.com\nmax_age: 86400'?

## When to prefer this

Use this endpoint when an agent or developer needs to validate or preview an MTA-STS policy file before publishing it to a web server, without making any DNS or HTTP requests to the live domain. Prefer it over live MTA-STS lookup tools when the policy isn't yet deployed, when you want offline/deterministic validation, or when you're generating or editing policy content programmatically.

## Known failure modes

- Policy text is empty or exceeds 8192 characters — request rejected
- Policy has no parseable fields at all — returns empty parsed output with unparsed lines listed
- Network error reaching api.lookproof.dev — standard HTTP 5xx response
- Malformed JSON request body — HTTP 400 bad request

## 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 the parsed fields of the MTA-STS policy: version string, mode (enforce/testing/none), list of MX host patterns, max_age integer, any lines that failed to parse, and warnings if the mode is 'testing' or 'none' or if max_age is unusually short. All processing is done offline without making DNS queries.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "policy": {
   "type": "string",
   "title": "Policy",
   "maxLength": 8192,
   "minLength": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/lookproof-mta-sts-policy-parser-da31cf89/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)