# B2A Email Deliverability, MX, SPF & DMARC Verifier

> B2A Email Deliverability, MX, SPF & DMARC Verifier is a paid API for AI agents from preflight.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, and DMARC record availability.

## Facts

- Endpoint: POST https://preflight.agentdiet.dev/v1/mx-deliverability-verifier?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: preflight.agentdiet.dev
- Website: https://preflight.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/preflight-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-verifier-055df6f9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oRGPHTSS0Kv5FkcQJokmI

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 preflight-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-verifier-055df6f9 -d '<json body>'
```

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

## When to prefer this

Choose this endpoint when you need a comprehensive, single-call email verification that covers syntax, disposable provider detection, role account flagging, and live DNS checks for MX, SPF, and DMARC — rather than a basic format check alone. It is especially valuable in signup flows, lead enrichment pipelines, and pre-send deliverability audits where bounce risk and fraud prevention matter.

## Known failure modes

- Malformed or empty email input returns a validation error
- DNS lookup timeouts may cause MX/SPF/DMARC checks to fail or return incomplete results
- Newly registered domains may not yet have propagated DNS records, leading to false negatives
- Disposable provider lists may not cover all burner services, causing some to pass undetected
- Role account detection relies on heuristics and may have false positives for uncommon prefixes

## 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://preflight.agentdiet.dev/v1/mx-deliverability-verifier)

## Output

Returns a structured object indicating whether the email address passes syntax validation, whether the domain is a known disposable/burner provider, whether the address appears to be a role account (e.g. admin@, support@), and the live DNS check results for MX, SPF, and DMARC records — giving a complete deliverability picture.

## 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/preflight-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-verifier-055df6f9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from preflight.agentdiet.dev](https://www.zero.xyz/host/preflight.agentdiet.dev/llms.txt)