# Email MX Readiness Check

> Email MX Readiness Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Validates caller-supplied MX records to determine if they contain usable, non-null mail exchanges, returning a deterministic pass/advisory verdict as structured JSON.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/email-mx-readiness-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/email-mx-readiness-check-fbf930f8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PU3q-MIlTPomEx3KS2izu

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 email-mx-readiness-check-fbf930f8 -d '<json body>'
```

Example prompt: Before I accept this email address from the form submission, can you check these MX records to make sure they have usable, non-null mail exchanges and pass the readiness check?

## When to prefer this

Choose this endpoint when you need a fast, deterministic, self-contained MX record readiness check with no external DNS dependency — ideal for validating caller-supplied MX data in-memory before accepting, caching, redirecting, or retrying a response. Prefer it over live DNS lookup tools when you already have the MX records in hand and want a bounded, reproducible verdict with explicit pass/advisory output.

## Known failure modes

- Malformed or empty records array returns an error or advisory status
- Records exceeding 256 items or objects exceeding 128 properties may be rejected
- Null or missing exchange fields in all records trigger an advisory (non-pass) verdict
- Payment failure via x402 protocol prevents the call from completing
- Invalid JSON structure in the records array causes a processing error

## How this service works

Email MX Readiness Check: Email MX Readiness Check checks caller-supplied MX records for usable non-null exchanges from bounded caller-supplied values without an external provider. Call Email MX Readiness Check before accepting, caching, redirecting, or retrying a caller-supplied web response. Returns normalized web evidence, the computed finding, and an explicit pass or advisory status for Email MX Readiness Check as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-part…

## Output

Returns versioned deterministic JSON containing: normalized evidence derived from the supplied MX records, a computed finding indicating whether usable non-null exchanges were found, and an explicit pass or advisory status verdict. No external DNS lookups are performed; all processing is in-memory using only the caller-supplied records.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "records": {
   "type": "array",
   "items": {
    "type": "object",
    "maxProperties": 128,
    "additionalProperties": true
   },
   "maxItems": 256,
   "description": "Records supplied to Email MX Readiness Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "ready": true,
   "usable_records": [
    {
     "exchange": "mx.example.com",
     "priority": 10
    }
   ]
  },
  "schema": "delx/util-email-mx-readiness-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "2f2f55bbb9bea419341f4467faeb92d47276b73be2a24e15557a35a2e9286b7e",
   "external_calls": 0
  },
  "operation": "web_reliability:email_mx_readiness_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/email-mx-readiness-check-fbf930f8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)