# 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, and DMARC record presence

## Facts

- Endpoint: GET https://prompt-guard.agentdiet.dev/v1/mx-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-dd2f8f82
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uCXnU1ExkEudUyXhm62fq

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-dd2f8f82
```

Example prompt: Can you check whether john.smith@acmecorp.com is a real, deliverable email — specifically whether it passes syntax checks, isn't a disposable burner address, and has valid MX, SPF, and DMARC DNS records set up?

## When to prefer this

Choose this endpoint when you need a comprehensive, single-call email check that combines syntax validation, disposable-provider detection, role-account flagging, and live DNS MX/SPF/DMARC record verification — particularly in B2B lead enrichment, user signup fraud prevention, or pre-campaign list hygiene workflows where deliverability and security posture matter. Prefer it over simple syntax-only validators when DNS record correctness is critical.

## Known failure modes

- Invalid or malformed email string provided — returns syntax error
- Domain does not exist or has no DNS records — MX/SPF/DMARC fields return absent/null
- DNS lookup timeout for the domain — may return partial results
- Rate limiting or payment failure (HTTP 402) if USDC micropayment is not settled
- Empty email parameter — required field validation 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/mx-check)

## Output

Returns a structured object indicating: email syntax validity, whether the domain uses a known disposable/burner email provider, whether the address is a role account (e.g. info@, admin@), and the presence/validity of live DNS MX, SPF, and DMARC records for the email domain — enabling a comprehensive deliverability and fraud-risk assessment.

## 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-dd2f8f82/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)