---
title: "Managed Domain"
description: "How the auto-issued *.primitive.email domain works and when to use it instead of a custom domain."
canonical: "https://docs.primitive.dev/docs/managed-inbox"
last-updated: "2026-05-17T00:00:00.000Z"
---

# Managed Domain

Every Primitive organization gets a managed `*.primitive.email` subdomain at signup. It is ready for inbound and outbound mail without user-managed DNS.

Example:


```
brave-otter.primitive.email
```


You can receive at any local-part under that domain, such as `support@brave-otter.primitive.email` or `agent+triage@brave-otter.primitive.email`.

## What Primitive Manages

Primitive owns and operates the parent DNS zone. For your managed subdomain, Primitive publishes the records needed for:

- inbound MX delivery;

- outbound DKIM signing;

- SPF alignment for Primitive-managed sends;

- DMARC reporting policy.

Because the records are managed by Primitive, verification is immediate.

## When to Use It

Use the managed domain for:

- first integrations and quickstarts;

- agent inboxes;

- internal automation;

- testing send and receive flows;

- workflows where Primitive-branded mail is acceptable.

Use a custom domain when recipients should see your brand in the address, or when you need mail to route for an existing domain.

## Sending from the Managed Domain

The CLI can auto-select a valid `from` address on the managed domain:


```
primitive send --to alice@example.com --body "hello" --wait
```

```
curl -X POST https://api.primitive.dev/v1/send-mail \
  -H "Authorization: Bearer $PRIMITIVE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"from":"agent@brave-otter.primitive.email","to":"alice@example.com","subject":"Hello","body_text":"hello","wait":true}'
```


In REST, pass an address on the managed domain explicitly:


```
{
  "from": "agent@brave-otter.primitive.email",
  "to": "alice@example.com",
  "subject": "Hello",
  "body_text": "Hi."
}
```


## Receiving on the Managed Domain

Inbound mail to the managed domain is accepted by Primitive MX and delivered to your active endpoints or Functions.

If no endpoint is active, the email is still stored and can be retrieved through the REST API.

## Subaddressing

Use plus tags for routing hints:


```
agent+github@brave-otter.primitive.email
agent+billing@brave-otter.primitive.email
```


The parsed payload preserves recipient addresses so your handler can branch on the local part.

## Moving to a Custom Domain

When you are ready for branded mail, add a domain in the dashboard, publish the DNS records, and wait for verification. The managed domain remains available after custom domains are added.

See [Domains](/docs/domains) for record details.

Maintained by the [primitive.dev team](/about) · [Trust & security](/trust)Last updated: May 17, 2026