# Email Deliverability Audit (SPF/DKIM/DMARC)

> Email Deliverability Audit (SPF/DKIM/DMARC) is a paid API for AI agents from sigtap-outreach-api.sigtap.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Audits a sending domain's SPF, DKIM, and DMARC DNS records to assess email deliverability health

## Facts

- Endpoint: GET https://sigtap-outreach-api.sigtap.workers.dev/deliverability
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/email-deliverability-audit-spf-dkim-dmarc-537b55b5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xPP4epPJPl-qPTT99WSZ9

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 email-deliverability-audit-spf-dkim-dmarc-537b55b5
```

Example prompt: Can you run a full SPF, DKIM, and DMARC deliverability audit on my sending domain acmecorp.com and tell me if there are any issues that might cause my emails to land in spam?

## When to prefer this

Choose this endpoint when you need a quick, automated SPF/DKIM/DMARC audit for a specific sending domain, especially before launching cold email or outreach campaigns. It is ideal for agents embedded in email tooling workflows where deliverability pre-checks are needed programmatically. Prefer this over manual DNS lookup tools when you want a structured, machine-readable audit result covering all three major email authentication standards in a single call.

## Known failure modes

- Domain not found or does not exist — DNS lookup failure
- Missing or malformed query parameter for domain
- Rate limit exceeded or payment failure for x402 micropayment
- DNS timeout or upstream resolver error
- Domain has no email-related DNS records configured

## How this service works

Paid micro-utilities for cold-email outreach agents: domain deliverability audits, cold-email grading, template generation, plus a tools toolbox (hashing, JWT decode, IDs, slugs, JSON, regex, crypto prices, domain age, weather). Paid via x402 (USDC on Base). One signature per call. No keys. FREE CHECK: GET /preview/<paid-path> (same URL with /preview/ prefix) returns a 200 demo sample - verify output shape before paying. PAID CALL: GET the url -> 402 challenge -> sign + retry with X-PAYMENT -> settled on-chain (USDC, Base). Ready-to-paste client: GET /llms.txt section "Pay in one call". Catalog+MCP twin: /llms.txt.

## Output

Returns a structured deliverability audit report covering the domain's SPF record validity, DKIM selector status, and DMARC policy configuration, including any misconfigurations, missing records, or policy weaknesses that could cause emails to be rejected or marked as spam.

## 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",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "example": {
  "spf": {
   "found": true,
   "issue": null,
   "record": "v=spf1 ...",
   "all_in_one": true
  },
  "dkim": {},
  "dmarc": {
   "found": true,
   "policy": "none"
  },
  "checks": {},
  "domain": "example.com",
  "verdict": "ready-to-send"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/email-deliverability-audit-spf-dkim-dmarc-537b55b5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sigtap-outreach-api.sigtap.workers.dev](https://www.zero.xyz/host/sigtap-outreach-api.sigtap.workers.dev/llms.txt)