FEATURE / INBOUND EMAIL

Email comes back. Send it straight to your code.

Receive mail at your domain, let Postal parse it on your own server, and get one webhook with the full message — headers, text, HTML, attachments, and the thread it belongs to. Replies become API calls. Support@ becomes a queue in your app.

One route in. One webhook out.

Point an address — or a whole domain with a catch-all — at mailstein. Every message that lands gets parsed and POSTed to your endpoint as structured JSON. No IMAP polling, no mailbox to babysit.

01 / ADDRESSES

Any address or catch-all

Route a single mailbox like support@ or reply@, or wildcard the whole domain so anything@yourdomain lands on your endpoint. Route different addresses to different webhooks.

02 / PARSED

MIME, already decoded

You get the plain-text body, the HTML body, subject, from/to/cc, message-id, and in-reply-to references — parsed out of the raw MIME so you never touch a base64 blob unless you want the raw source too.

03 / THREADED

Replies that reconnect

Inbound messages carry their In-Reply-To and References headers, so a customer reply maps back to the exact transactional email you sent. Close the loop between outbound and inbound in one platform.

THE PAYLOAD

Everything about the message, in one POST

mailstein delivers a single JSON body to your webhook the moment mail arrives. Verify the signature, read the fields you need, and act — reply, ticket, tag, or store. Attachments come inline as base64 or as short-lived download URLs, your choice per domain.

// POST from mailstein → your webhook { "event": "inbound.received", "to": "support@boardpearls.com", "from": "dr.lee@clinic.io", "subject": "Re: Your receipt", "in_reply_to": "<a1b2@mailstein>", "text": "Thanks — can you refund...", "html": "<p>Thanks — can you...</p>", "attachments": [{ "name": "eob.pdf" }], "spf": "pass", "dkim": "pass" }

Because it runs on your infrastructure

Inbound mail is received and parsed by the Postal MTA on your own server. The message body never has to live in someone else's log.

DELIVERABILITY-AWARE

SPF & DKIM come attached

Every inbound payload includes the authentication result, so you can trust a reply before you act on it — auto-file the passes, quarantine the spoofs.

A "reply from your customer" that fails SPF and asks to change payout details is exactly the one you want flagged, not auto-ticketed.
YOUR DATA

Parsed on your box, not a middleman's

Because reception runs on your own server and IP, the raw inbound content and its logs stay under your control — a real difference when the mail contains anything you'd rather not hand to a SaaS vendor.

Support inboxes collect invoices, personal details, sometimes worse. With mailstein that content is parsed and forwarded from infrastructure you own.

Turn your inbox into an endpoint.

Free tier: 50 emails a month and one domain, no card. Add an inbound route and point your webhook in minutes.

Start free