# B2A Email Deliverability, MX, SPF & DMARC Verifier

> B2A Email Deliverability, MX, SPF & DMARC Verifier is a paid API for AI agents from prompt-guard.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-21).

Validates an email address for syntax correctness, disposable/burner domain status, role account detection, and live DNS MX, SPF, and DMARC record verification.

## Facts

- Endpoint: GET https://prompt-guard.agentdiet.dev/v1/email-check?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: prompt-guard.agentdiet.dev
- Website: https://prompt-guard.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/prompt-guard-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-8e563955
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mvS6RKM0kx4InqF9Dajm0

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 prompt-guard-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-8e563955
```

Example prompt: Can you check whether john.doe@acmecorp.com is a real, deliverable email — I want to know if the domain has valid MX records, whether it passes SPF and DMARC, and if it looks like a disposable or role account?

## When to prefer this

Choose this endpoint when you need a comprehensive, single-call email check covering syntax, disposable provider detection, role account identification, and live DNS verification of MX, SPF, and DMARC records — particularly for B2B lead validation, fraud prevention during user signup, or pre-send list hygiene in marketing workflows. Prefer it over simple syntax-only validators when DNS deliverability and email security posture (SPF/DMARC) matter to your use case.

## Known failure modes

- Missing or empty email parameter returns a validation error
- Malformed email string may return syntax-invalid without DNS checks
- DNS lookup timeout for obscure or slow-responding domains may produce incomplete MX/SPF/DMARC results
- Non-existent TLD or domain returns no MX records found
- Payment not fulfilled (HTTP 402) blocks response if x402 payment not completed

## How this service works

Validates email syntax, disposable/burner provider status, role accounts, and live DNS MX/SPF/DMARC records. (Live x402 v2, IETF MPP & MCP endpoint at https://prompt-guard.agentdiet.dev/v1/email-check)

## Output

Returns a structured object indicating email syntax validity, whether the domain uses a known disposable/burner provider, whether it is a role-based address (e.g. info@, admin@), and live DNS lookup results for MX, SPF, and DMARC records — helping determine overall deliverability and trustworthiness of the address.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "email"
 ],
 "properties": {
  "email": {
   "type": "string",
   "minLength": 1,
   "description": "Email address to validate for syntax, MX deliverability, and disposable risk"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/prompt-guard-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-8e563955/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from prompt-guard.agentdiet.dev](https://www.zero.xyz/host/prompt-guard.agentdiet.dev/llms.txt)