Catch the obvious problems before you send.
Email Preflight checks syntax, mail routing, disposable-domain matches and likely typos. Every DNS finding comes with its evidence.
Not accepting payments yet. Launch configuration is in progress.
A small, specific job
Use this when an agent needs to filter obvious address problems before spending time on deeper mailbox verification. It does not send mail or contact the recipient's mailbox.
| Check | What you get |
|---|---|
| Address and domain | Syntax, internationalized domain normalization, typo suggestions. The mailbox name is preserved. |
| Mail routing | MX hosts, explicit null MX, and A/AAAA fallback when there is no MX record. |
| List and rule matches | Versioned disposable-domain list, role accounts and a small free-provider list. A non-match is not a guarantee. |
| Sending authentication | SPF and exact-domain DMARC presence. These do not prove a recipient can receive mail. |
Call it from your agent
POST /api/agent/email-preflight
{"email":"person@example.com"}Send this JSON with Content-Type: application/json. When payments are live, the first request returns HTTP 402 with the exact price and Base USDC payment terms. A compatible x402 v2 client signs the payment and retries. No SHSY account or API key.
Bounded-price Node client · Agent instructions · Request schema · Complete static example
Know exactly what it means
- Mailbox existence and deliverability are always “unknown.” This is not an SMTP, catch-all, spam reputation or inbox placement test.
- “Continue” means continue checking. It is not permission or a recommendation to send email.
- Temporary DNS failure returns 503. We do not request payment settlement for incomplete DNS evidence.
- No made-up confidence score. Decisions follow explicit rules and observed records.
Privacy and receipts
The email is sent in the request body, never in a URL. We do not persist the email or full result. The DNS resolver receives the domain. Payment verification receives protocol metadata; discovery examples use a reserved example address, never your submitted email.
Operational records include request IDs, quoted prices, response status, timing, hashed payer identifiers and settlement transaction hashes. Public-chain payment records remain public. If payment succeeded but the connection broke, contact sj@someonehastosayyes.com with the request ID and transaction hash before paying again.