Linje

Product email infrastructure

Transactional email and inbound webhooks.

Send the email your product depends on. Let customers reply normally, then deliver each answer to the right application object. Keep the delivery trail inspectable when something fails.

HTTP to email Email to HTTP Receipts Magic links Replies No campaigns
Contact Read docs

Outgoing

Your app sends product email.

Use one API for receipts, magic links, password resets, invites, and alerts.

Your app Linje Recipient inbox 
POST /v1/messages
{
  "from": "auth@tx.example.com",
  "to": ["you@example.com"],
  "subject": "Your sign-in link"
}

Incoming

Incoming email returns to your app.

Use an inbox directly or forward mail into one. Linje sends your endpoint a signed payload with the message and attachments.

Mail Linje inbox Your endpoint 
POST /v1/inboxes

POST https://app.example.com/inbound
{
  "inbound-id": "...",
  "email": {
    "from": [{"email":"user@example.com"}],
    "subject": "Reply"
  },
  "attachments": [...]
}

Replies

A reply returns to the object that sent it.

Generate an opaque Reply-To address with caller metadata. Linje maps the reply back without exposing a business identifier in the address.

Application object Reply address Webhook event 
POST /v1/reply-routes
Idempotency-Key: 018f47d2-89ab-4cde-8123-456789abcdef
{"inbox-id":"orders",
 "metadata":{"order-id":"order_82921"}}

WEBHOOK
"route": {
  "id": "route_...",
  "metadata": {"order-id":"order_82921"}
}

Reliability

The delivery trail is part of the product.

Linje stores the email event before callback delivery and keeps attempts visible when your endpoint or the mail path fails.

Durable history

Inspect message status, delivery attempts, bounces, and webhook responses.

Retry and replay

Automatic backoff handles transient failures. Replay the same event without creating a new email.

Signed artifacts

Verify callbacks with HMAC signatures and retrieve raw messages and attachments through controlled references.

Product boundary

One small service with a clear job.

Linje handles product email in both directions, then gets out of the way. Business workflows stay in your app.

HTTP to email

Send receipts, magic links, password resets, invites, and alerts.

Email to HTTP

Turn inbound email and attachments into signed webhook events.

No ESP creep

No campaigns, lists, open tracking, click tracking, or workflow builder.

Common jobs

Start where email touches your product.

Transactional Email API Send the product messages users expect to receive. Inbound Email Webhooks Receive email and attachments inside your application. Email to Webhook Turn replies and inbound addresses into application events. Reply by Email API Route customer replies to the right order, ticket, invoice, or application object. Webhook Replay Recover cleanly when a downstream handler was down.

Pricing

Simple usage pricing.

Pricing is based on messages processed each month.

One outbound email is one message. One inbound email delivered to your webhook is one message. Creating and keeping reply routes does not consume message usage.

Plan Monthly usage Price
Starter 500 messages / month Free
Growth 5,000 messages / month $5 / month
Scale 50,000 messages / month $25 / month