Email security
Full email auth posture: SPF, DMARC, DKIM, and composite deliverability score in one call.
4 tools run server-side in one request. You pay once, settle once, and get a single response - no orchestration, no per-step payments, and a partial-success envelope if any step fails. USDC over x402 on any supported chain.
When to use this pack
Diagnosing email authentication - can this domain be spoofed, and is its mail configuration complete.
Tools in this pack
All 4 run inside the single $0.006 call above. Each is also callable on its own if you only need one part.
- SPF check POST /api/spf-check Fetch and validate a domain's SPF record (RFC 7208). Parses mechanisms (ip4/ip6/include/a/mx/all), counts DNS lookups against the famous 10-lookup limit, and flags the qualifier on `all` (-/fail, ~/softfail, ?/neutral). The first stop when an email is hitting the spam folder.
- DMARC check POST /api/dmarc-check Fetch and validate a domain's DMARC policy at _dmarc.<domain> (RFC 7489). Surfaces the enforcement policy (none/quarantine/reject), reporting addresses, alignment modes, and common misconfigs (no rua, p=none stuck for months, percent <100). Pair with SPF and DKIM for full Feb-2024 sender-rule compliance.
- DKIM key lookup POST /api/dkim-lookup Fetch and parse a DKIM public-key record at <selector>._domainkey.<domain> (RFC 6376). Returns the parsed key params (algorithm, length, flags) so you can verify rotation status or key strength. Caller must know the selector - use email-deliverability if you don't.
- Email deliverability check POST /api/email-deliverability End-to-end email-auth report for a domain: SPF + DMARC + DKIM (probes common selectors automatically) + MX records + score 0–100. The one call to make when 'why is our mail going to spam?' lands in your inbox.
Bought one at a time, these 4 tools cost $0.006 together; the pack is that sum less a 10% bundle discount, rounded up to the $0.001 settlement floor, which is $0.006.
Workflow
- Parse the SPF record - flag permissive +all, excessive lookups, or syntax errors.
- Parse the DMARC policy - p=none means failures are ignored.
- Probe common DKIM selectors and check key strength.
- Run the composite deliverability score for an overall grade.
Arguments
| Name | Required | Description | Example |
|---|---|---|---|
domain | yes | Domain to check (e.g. stripe.com) | stripe.com |
What one call returns
A JSON object with pack, args, steps, summary; steps holds one entry per tool (spf-check, dmarc-check, dkim-lookup, email-deliverability), each with its own result or error. Full example on the API page.
Call it directly
Any x402 client pays the 402 and gets the whole workflow back in one response. With the agent402-client SDK (npm i agent402-client, an ES module):
import { Agent402 } from "agent402-client";
// payFetch: an x402-wrapped fetch your wallet signs (@x402/fetch).
// Tools on the free tier need no options: new Agent402() pays them by proof-of-work.
// an existing prepaid credits key also works: new Agent402({ creditsKey })
const client = new Agent402({ fetch: payFetch });
const result = await client.call("skill-email-security", {"domain":"stripe.com"});
Run it in Claude
claude mcp add agent402 -s user -- npx -y agent402-mcp@latest
Then paste this prompt into Claude:
Check email security for stripe.com using Agent402's email-security skill pack. Get (1) SPF check, (2) DMARC policy, (3) DKIM probe, (4) deliverability score. Flag any missing or weak auth records.