# B2A Email Deliverability, MX, SPF & DMARC Verifier

> B2A Email Deliverability, MX, SPF & DMARC Verifier is a paid API for AI agents from onchain-risk.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 checks.

## Facts

- Endpoint: POST https://onchain-risk.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: onchain-risk.agentdiet.dev
- Website: https://onchain-risk.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/onchain-risk-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-012fbf82
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xBBY3GvkXJ_F7Jhb4uSN2

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 onchain-risk-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-012fbf82 -d '<json body>'
```

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

## When to prefer this

Choose this endpoint when you need a single, comprehensive email quality check combining syntax validation, disposable provider detection, role account flagging, and live DNS MX/SPF/DMARC lookup in one call — especially in agentic workflows processing user signups, lead lists, or outreach targets where deliverability and authentication posture matter together.

## Known failure modes

- Malformed or missing email input returns a validation error
- DNS lookup timeout if the queried domain is unreachable or extremely slow
- Disposable provider list may lag behind newly created throwaway domains
- Role account detection based on username prefix heuristics may produce false positives for legitimate addresses
- API payment failure via x402 if USDC balance is insufficient

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

## Output

Returns a structured object indicating email syntax validity, whether the domain is a known disposable/burner provider, whether the address is a role account (e.g. info@, admin@), live DNS MX record presence and details, SPF record existence and content, and DMARC policy record status — giving a comprehensive deliverability risk assessment.

## 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/onchain-risk-agentdiet-dev-b2a-email-deliverability-mx-spf-dmarc-012fbf82/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchain-risk.agentdiet.dev](https://www.zero.xyz/host/onchain-risk.agentdiet.dev/llms.txt)