# 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 2026-10-23).

Validates an email address for syntax correctness, disposable/burner provider status, role account detection, and live DNS MX/SPF/DMARC record checks to confirm deliverability.

## Facts

- Endpoint: POST https://prompt-guard.agentdiet.dev/v1/email-verify?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- 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-cc73b5f2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_j80HgqMGioDTB4OFAuwhP

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-cc73b5f2 -d '<json body>'
```

Example prompt: Can you check whether john.doe@example.com is a real, deliverable email address — including whether the domain has valid MX records, passes SPF and DMARC checks, and isn't a disposable or role-based address?

## When to prefer this

Choose this endpoint when you need a comprehensive, multi-signal email validation that goes beyond simple syntax checks — combining live DNS MX/SPF/DMARC lookups with disposable provider and role account detection in a single call. Prefer it over basic regex validators when lead quality, email campaign deliverability, or user signup fraud prevention is the goal.

## Known failure modes

- Invalid or malformed email string returns a syntax error flag
- Domain with no MX records results in undeliverable verdict
- DNS lookup timeout may result in inconclusive MX/SPF/DMARC status
- Disposable provider databases may have coverage gaps for very new burner services
- Payment failure via x402 returns HTTP 402 before validation occurs

## 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-verify)

## Output

Returns a structured object indicating: email syntax validity, whether the domain is a known disposable/burner provider, whether the address is a role account (e.g. info@, support@), live MX record presence and details, SPF record validity, DMARC record presence and policy, and an overall deliverability verdict.

## 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-cc73b5f2/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)