# 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-deliverability-verifier?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-1d3da08e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_s3TK8bOOFtCQj0avdUsC7

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-1d3da08e
```

Example prompt: Can you check whether john.doe@example.com is a real, deliverable email address — specifically if it has valid MX records, isn't a disposable or burner address, and has SPF and DMARC records set up on the domain?

## When to prefer this

Choose this endpoint when you need a comprehensive, real-time email quality check combining syntax validation, live DNS MX/SPF/DMARC lookups, disposable provider detection, and role account flagging in a single call — particularly useful before adding contacts to a CRM, launching email campaigns, or validating user signups to reduce bounce rates and fraud. Prefer this over simple syntax-only validators when deliverability confidence and anti-abuse signals are important.

## Known failure modes

- Invalid or malformed email input returns a syntax error or validation failure
- Domain has no MX records — domain exists but cannot receive email
- DNS lookup timeout or transient DNS failure may cause inconclusive results
- Disposable provider database may not cover brand-new or obscure throwaway services
- Rate limiting or payment failure (HTTP 402) if payment is not properly handled

## 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-deliverability-verifier)

## Output

Returns a structured object indicating whether the email address is syntactically valid, whether the domain has live MX records (confirming mail can be received), SPF and DMARC record presence and configuration, whether the address belongs to a known disposable or burner email provider, and whether it appears to be a role account (e.g. admin@, info@, noreply@).

## 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-1d3da08e/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)