Postbox is a headless, API-first email platform. Send, receive, store, read — every mailbox capability your app needs, behind one SDK. No SMTP relay stitching. No IMAP servers to babysit.
Most "email APIs" only solve one direction. Postbox is the full backend — send, receive, store, read — composable as a single primitive.
Outbound through Amazon SES with per-domain DKIM, SPF, and DMARC handled. Per-mailbox sender rules and rate limits enforced before anything leaves the queue.
Inbound MX runs spam scoring, parses MIME, resolves threading, and fires a webhook the moment a message is stored in the right folder.
Mailbox storage with attachments, threads, folders, and read state. Fully queryable per user, per mailbox, with retention you control.
Paginated reads and mailbox-scoped tokens, so an end user's client can read exactly one inbox — and nothing else — without touching your backend.
Postbox sits between the public mail network and your application. DNS, SMTP, spam filtering, and storage live on our side; your code talks REST and webhooks.
Subscribe once, get a signed, typed payload for every send, receive, bounce, and domain event — delivered at-least-once with per-endpoint delivery logs you can inspect from the dashboard.
Same call, three runtimes. The response on the right is the shape you get back from POST /messages/send.
If your users expect to read and reply — not just receive a receipt — you need full mailbox semantics. That's what Postbox is for.
Issue students a real @school.edu mailbox in one API call. Postbox handles DNS and retention policy; you keep the roster logic.
Spin up a per-reservation mailbox. Inbound replies route to the right front-desk queue. Auto-archive on checkout.
Own the help@ mailbox. Threading, assignment, and SLA logic stay in your product. Postbox is the pipe and the store.
Every notification gets a unique reply address. Inbound mail comes back parsed and keyed to the thread it belongs to.
Provision an email address before laptop day. Tear down on offboarding with one DELETE, archive intact.
Multi-tenant from day one. Your end customers get their own domain, their own DKIM, their own reputation — through your brand.
Every tier includes a monthly email allowance (send + receive combined). Go past it and you pay a simple metered rate — or upgrade.