# 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 provider status, role account detection, and live DNS MX/SPF/DMARC record lookups to assess deliverability.

## Facts

- Endpoint: GET https://prompt-guard.agentdiet.dev/v1/disposable-email?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-85dad1a9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5oidqvEL2pEoxuALJ99LX

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-85dad1a9
```

Example prompt: Can you check if john.doe@tempmail.com is a real, deliverable email address — specifically whether it's a disposable/burner provider, has valid MX records, and passes SPF and DMARC checks?

## When to prefer this

Choose this endpoint when you need a comprehensive, real-time email hygiene check combining syntax validation, disposable provider detection, role account identification, and live DNS MX/SPF/DMARC record verification in a single call. It is particularly useful for sign-up fraud prevention, sales lead qualification, and pre-campaign deliverability audits. Prefer it over simple regex validators when you need live DNS truth, and over domain-only tools when per-address disposable/role detection is required.

## Known failure modes

- Missing or empty email parameter returns an error
- Malformed email string may return syntax invalid without DNS checks
- Temporary DNS lookup failures may result in inconclusive MX/SPF/DMARC results
- Rate limiting or payment failure (HTTP 402) if per-call USDC payment is not provided
- Unknown or newly registered domains may lack SPF/DMARC records, returning absent status rather than an error

## 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/disposable-email)

## Output

Returns a structured object indicating whether the email passed syntax validation, whether the domain is a known disposable/burner provider, whether it is a role-based account (e.g. admin@, noreply@), and the live DNS lookup results for MX, SPF, and DMARC records for the email's domain.

## 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-85dad1a9/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)