# 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/DMARC record checks to assess deliverability.

## Facts

- Endpoint: POST https://preflight.agentdiet.dev/v1/email-check?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-168364cc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dHTzurke_jFtaacR0NJpR

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-168364cc -d '<json body>'
```

Example prompt: Can you check if john.doe@acmecorp.com is a real, deliverable email address — verify its syntax, check whether it's from a disposable provider, and confirm there are valid MX, SPF, and DMARC records on the domain?

## When to prefer this

Choose this endpoint when you need a comprehensive, multi-layer email validation that goes beyond simple syntax checking — combining disposable-provider detection, role-account flagging, and live DNS MX/SPF/DMARC lookups in a single call. Ideal for agent-driven onboarding flows, B2B lead enrichment pipelines, or pre-send deliverability checks where bad email quality would waste resources or damage sender reputation. Prefer this over basic regex validators or single-purpose DNS tools when you want a single authoritative pass/fail signal with full diagnostic detail.

## Known failure modes

- Empty or missing email field returns a 400 validation error
- Malformed email that fails syntax check returns invalid syntax flag rather than performing DNS lookups
- DNS lookup timeouts for obscure or slow-responding domains may return incomplete MX/SPF/DMARC data
- Newly registered domains may not yet have propagated DNS records, leading to false negatives
- Disposable provider list may not cover every burner domain, allowing some to pass undetected
- Payment failure or insufficient balance returns HTTP 402 before any validation is performed

## 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/email-check)

## Output

Returns a structured object indicating email syntax validity, whether the domain belongs to a known disposable/burner email provider, whether the address is a role account (e.g. info@, admin@), and the live DNS lookup results for MX, SPF, and DMARC records — allowing the caller to assess overall email deliverability and quality risk.

## 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-168364cc/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)