Mailway documentation

Private beta

Mailway is in private beta, and we onboard teams one at a time. Join the waitlist and we'll email your invite — everything below works the moment you're in.

Mailway keeps a byte-for-byte copy of every email your app sends: an archive that works as your app’s Sent folder. Each mail’s timeline in the console shows what happened to it, its delivery history. Mailway sends through your own provider accounts (for example Amazon SES, SendGrid, Mailgun, or Postmark) and fails over between them when one refuses. Your apps talk to Mailway over SMTP or the HTTP API.

Bring your own keys. Mailway is not an email provider — it sits between your app and the provider you already have. You keep your provider relationship, your reputation, and your pricing; Mailway adds the archive, failover and routing, the delivery history, and proof of what was sent.

Get started

SMTP quickstartPoint your app at smtp.mailway.net and send your first mail in five minutes — no code changes beyond an .env file.

HTTP APIPOST /v1/send — JSON in, a 202 and a mail ID out. Idempotency, batching, scheduling, and per-message provider routing.

Bring your own keysAttach your provider accounts, order the failover chain, and wire Amazon SES delivery events in fifteen minutes.

WebhooksSeven lifecycle events, HMAC-SHA256 signatures with a timestamp, automatic retries. Know when mail is delivered, bounces, or is marked as spam.

Ruleswhen / if / then — tag, route, hold, or reject mail at the gateway instead of in every app.

Share links & proof of deliveryShow anyone exactly what was sent, and prove it with a signed certificate that verifies offline.

DeliverabilitySPF, DKIM, and DMARC live at your provider under BYOK — what each record proves, and how to verify alignment before you send.

TroubleshootingFind your symptom — auth errors, stuck mail, bounces, quotas, webhooks — and map it to a cause and a fix.

How a send flows

1. Your app hands Mailway a message — over SMTP or POST /v1/send.
2. Mailway receives it, stores it, runs your rules, and picks a provider from the ones you attached to the project.
3. If a provider refuses the send (a rejected key, exhausted credits, a throttle), Mailway fails over to the next attached provider, five seconds later when it’s one the mail hasn’t tried, so the send survives a provider outage. Failover needs at least two providers on the project (Pro and up).
4. Delivery confirmations, bounces, and complaints stream back in from the provider — normalized into one delivery history whichever provider reported them — onto your webhooks, and into the project’s suppression list, where a bounce learned through one provider protects sends through every provider in that project.
5. The full message — headers, body, and attachments — is archived byte-for-byte, so the console can show you exactly what was sent, and prove it.

Two environments

Host	Purpose
smtp.mailway.net / api.mailway.net	Production — messages relay to your providers. Live API keys (mw_live_…) work only here.
smtp.mailway.dev / api.mailway.dev	Sandbox — mail is captured: stored and visible in the console, but never forwarded automatically. Delivery only happens if you release a capture from the console. Test keys (mw_test_…) for the HTTP API.

The payload shape is identical in both environments, so switching to production is a hostname and key change — nothing else.