# Email delivery

URL: /systems/communications/email · Id: `capability:email`

> Email delivery sends and receives email from warmed, authenticated Mailboxes, and checks Consent and Suppression before every send.

Email delivery sends and receives email from authenticated, warmed [Mailboxes](/business/nouns/mailbox). Every send passes [Consent](/business/nouns/consent), [Suppression](/business/nouns/suppression) and [Guard](/business/nouns/guard) checks first.

## Contract
- Every [Agent](/business/nouns/agent) has its own Mailbox and sends as itself. A Mailbox lives at a [Domain](/business/nouns/domain) the [Startup](/business/nouns/startup) holds, authenticated for sending when the Domain connects.
- Before each send, delivery reads Suppression across every Startup of the [Company](/business/nouns/company), checks Consent for the [Message](/business/nouns/message)'s [Purpose](/business/nouns/purpose), and runs its Guards. A failed check refuses the send.
- Bounces, complaints and unsubscribes add a Suppression at once.
- Cold outreach sends only from outreach Domains, never from a [Brand](/business/nouns/brand)'s primary Domain. A new outreach Mailbox ramps to 30 sends a day over its warm-up.
- Inbound mail arrives at the Domain and joins its [Thread](/business/nouns/thread) as a Message.
- Each Message has one id. Edits are revisions, and deletes are markers.
- Open and click tracking is off unless the Startup turns it on.
- [Messaging](/systems/communications/messaging) covers the other mediums: SMS, voice and chat.

## Verbs
| Verb | Object | Event |
| --- | --- | --- |
| [Message.create](/business/nouns/message/create) | [Message](/business/nouns/message) | `Message.created` |

## Interfaces
- [API](/code/api/reference)
- [SDK](/code/sdk/reference)
- [CLI](/code/cli/reference)
- [MCP](/code/mcp/reference)

## Example
```ts
// fieldnotes.school sells a birding course. Its success agent welcomes each new student.
import { $ } from 'startup-builder'

await $.Message.create({
  medium: 'email',
  direction: 'outbound',
  from: 'success@fieldnotes.school',
  to: 'ana@example.com',
  purpose: 'onboarding',
  subject: 'Your first field walk',
  body: 'Welcome to Fieldnotes. Your first field walk is Saturday at 7 a.m.; bring binoculars if you have them.',
})
// Refused with reason "suppressed" if the address unsubscribed from any of the Company's senders.
```