# 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 checks.

## Facts

- Endpoint: GET https://prompt-guard.agentdiet.dev/v1/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-f0765224
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_25dnvR33pir-5WP4xifYO

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-f0765224
```

Example prompt: Can you check whether john.doe@examplecorp.com is a real, deliverable email address — verify its syntax, check if the domain has MX records, and flag it if it's a disposable or role-based address?

## When to prefer this

Choose this endpoint when you need a comprehensive, multi-signal email validation that combines syntax checking, disposable/burner detection, role-account identification, and live DNS record lookups (MX, SPF, DMARC) in a single call. It is especially well-suited for AI agent workflows that need to verify email quality before outreach, onboarding, or lead enrichment, particularly in B2B or fraud-sensitive contexts. Prefer it over simple regex-based validators when you need live DNS confirmation of deliverability, or over domain-only tools when you need the full email address validated end-to-end.

## Known failure modes

- Missing or empty email parameter returns a 400 error
- Malformed email string may return syntax-invalid without DNS checks
- DNS timeout or unreachable authoritative nameserver may result in incomplete MX/SPF/DMARC results
- Payment not received (HTTP 402) if x402 micropayment is not completed
- Very new or obscure domains may not be in disposable provider lists yet, leading to false negatives
- Rate limiting if called too frequently without proper payment flow

## 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)

## Output

Returns a structured object indicating: whether the email syntax is valid, whether the domain is from a known disposable/burner provider, whether it is a role account (e.g. info@, admin@, noreply@), and the live DNS lookup results for MX, SPF, and DMARC records — giving a comprehensive deliverability and authenticity picture for 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-f0765224/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)