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Mail

Mail

Mail is the email service for your product. Send transactional email from your own domain over the API, then read what happened to each message. The same domain also routes inbound mail, so receipts go out and replies come back through one place.

Send transactional email

Mint an API key for your Mail app in the console. Keys look like smb_mail_…, and sending is scoped to the domain that Mail app has verified.

curl -X POST https://api.smbcloud.xyz/v1/email/messages \
  -H "Authorization: Bearer smb_mail_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "billing@example.com",
    "to": ["customer@acme.com"],
    "subject": "Your receipt",
    "html": "<h1>Thanks!</h1>",
    "idempotency_key": "receipt-2026-0001"
  }'

At least one of html or text is required, and from must sit on the verified domain. Messages also take cc, bcc, reply_to, base64 attachments, custom headers, and tags.

Reuse an idempotency_key and you get the original message back instead of a second send, which is what you want when a retry fires after a timeout.

From Rust, use smbcloud-email-sdk:

let message = SendEmail::new("billing@example.com", ["customer@acme.com"])
    .subject("Your receipt")
    .html("<h1>Thanks!</h1>")
    .idempotency_key("receipt-2026-0001");
 
let sent = client.send(&message).await?;

Track delivery

Every message carries a status: queued, sent, delivered, bounced, complained, or failed. Fetch one message for its full event timeline, or list recent messages filtered by status when you want to see what bounced.

curl "https://api.smbcloud.xyz/v1/email/messages?status=bounced&limit=20" \
  -H "Authorization: Bearer smb_mail_your_read_key"

Reading messages needs a read-scope key. Sending keys cannot read.

Receive and route

A Mail app maps to one domain and holds many inbox routes. Each route forwards inbound mail where it needs to go, and stores the message so you keep the history.

  • Run one Mail app per domain
  • Set up many inbox routes on a Mail app
  • Forward inbound mail where it needs to go
  • Store inbound message history

A project can have many Mail apps. The domain setup, meaning DNS, bucket, prefix, and shared routing, lives on the Mail app’s setup page, out of the way of everyday inbox work.

Getting started

  1. Create a Mail app for your domain.
  2. Complete the domain setup (DNS and routing) on the Mail app’s setup page.
  3. Mint an API key to send, or add inbox routes to receive.

Mail handles transactional email and domain routing. It is not a hosted mailbox suite: for business mailboxes you read in an app, see smbCloud Mail for business .

From the CLI or an AI agent

smb mail manages Mail apps and inbox routes from the terminal, and the same operations are available to Claude, Cursor, and other agents through the MCP server.

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