# 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 detection, role account flags, and live DNS MX, SPF, and DMARC record checks to determine deliverability.

## Facts

- Endpoint: GET https://prompt-guard.agentdiet.dev/v1/email-validator?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-2ba97e85
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Rkre1aYdxZCTSRr7kSSMH

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-2ba97e85
```

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

## When to prefer this

Choose this endpoint when you need comprehensive, multi-signal email validation in a single call — covering syntax, disposable/burner detection, role account flagging, and live DNS MX/SPF/DMARC verification simultaneously. It is particularly well-suited for B2B lead enrichment pipelines, signup fraud prevention, and pre-send email campaign hygiene checks where deliverability confidence matters. Prefer it over basic regex-only validators when real DNS health checks are required.

## Known failure modes

- Missing or malformed email parameter returns a validation error
- DNS lookup timeouts for domains with misconfigured or slow nameservers
- False negatives on newly registered disposable domains not yet in blocklists
- Payment failure or HTTP 402 if x402 payment is not properly handled
- Empty or null email string rejected by minLength constraint

## 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-validator)

## Output

Returns a structured object indicating whether the email address passes syntax validation, whether the domain is associated with a known disposable or burner provider, whether it appears to be a role account, and the live DNS lookup results for MX, SPF, and DMARC records on the domain.

## 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-2ba97e85/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)