# 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 2026-10-21).

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

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/email-check?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- 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-c8c59bba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r-Q7u53FtueLgtUSrsqbO

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-c8c59bba
```

Example prompt: Can you check whether john.smith@example.com is a real, deliverable email address — specifically whether the domain has valid MX records, passes SPF and DMARC, and isn't from a disposable or burner provider?

## When to prefer this

Choose this endpoint when you need a comprehensive, real-time email deliverability check that combines syntax validation, live DNS MX/SPF/DMARC record lookups, disposable provider detection, and role account flagging in a single call. Prefer it over simple regex or static blocklist tools when you need authoritative DNS-level confirmation that an email domain is actually configured to receive mail, especially for lead qualification, signup fraud prevention, or pre-campaign list hygiene.

## Known failure modes

- Invalid or malformed email address provided — returns syntax error
- Domain has no MX records — email cannot receive mail, flagged as undeliverable
- DNS lookup timeout or transient failure — may return partial results or error
- Payment not processed (x402) — endpoint returns 402 Payment Required
- Rate limiting exceeded — returns 429 Too Many Requests

## 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 whether the email passed syntax validation, whether the domain has live MX records capable of receiving mail, SPF and DMARC DNS record presence and validity, whether the provider is a known disposable or burner service, and whether the address appears to be a role account (e.g. info@, admin@).

## 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-c8c59bba/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)