> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lettr.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Domains Introduction

> Configure and verify the four domain types Lettr supports for sending, tracking, receiving, and storing email assets on your own domain

Domains are the foundation of your email infrastructure in Lettr. When you send emails through Lettr, email providers like Gmail and Outlook verify that you're authorized to send on behalf of your domain. Without proper domain configuration, your emails may be rejected or filtered to spam folders.

Lettr uses DNS records to establish this authorization. By adding specific records to your domain's DNS settings, you prove ownership and grant Lettr permission to send, track, and receive emails on your behalf. This process, called domain verification, enables email authentication protocols like SPF, DKIM, and DMARC that are now required by major email providers.

Depending on your needs, you can configure different domain types for different purposes. Most users start with a sending domain to authenticate outbound emails, then add tracking and storage domains to maintain brand consistency across all email components.

## Domain Types

Lettr supports four types of domains, each serving a specific purpose:

| Domain Type                                        | Purpose                          | Key Features                    |
| -------------------------------------------------- | -------------------------------- | ------------------------------- |
| [Sending Domain](/learn/domains/sending-domains)   | Send emails from your domain     | SPF, DKIM, DMARC authentication |
| [Tracking Domain](/learn/domains/tracking-domains) | Custom tracking links and pixels | HTTPS with auto-provisioned SSL |
| [Inbound Domain](/learn/domains/inbound-domains)   | Receive emails at your domain    | MX record configuration         |
| [Storage Domain](/learn/domains/storage-domains)   | Host email assets and content    | Custom CDN for images and files |

## Why Verify Domains?

Domain verification establishes your identity as a legitimate sender:

* **Inbox placement** — Properly authenticated emails pass SPF and DKIM checks, which is the primary signal email providers use to decide whether to deliver your message to the inbox or filter it to spam
* **Brand recognition** — Send from your own domain rather than a shared one, reinforcing your brand with every email
* **Compliance** — Major email providers — including Google and Yahoo — now require SPF, DKIM, and DMARC authentication for bulk senders
* **Spoofing protection** — Domain authentication lets receiving servers reject forged messages that claim to come from your domain

## Quick Start

<Steps>
  <Step title="Add Domain in Dashboard">
    Go to **Domains** → **Sending** → **Add Domain** and enter your domain name.
  </Step>

  <Step title="Add DNS Records">
    Add the provided SPF, DKIM, and DMARC records to your DNS provider.
  </Step>

  <Step title="Verify Domain">
    Click **Verify** to confirm DNS propagation. This may take a few minutes.
  </Step>
</Steps>

## Add Domain via API

Register a new sending domain with `POST /domains`. The request body contains only the domain name:

Create a sending domain:

```bash theme={null}
curl -X POST https://app.lettr.com/api/domains \
  -H "Authorization: Bearer lttr_xxxxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "domain": "example.com"
  }'
```

Response:

```json theme={null}
{
  "message": "Domain created successfully.",
  "data": {
    "domain": "example.com",
    "status": "pending",
    "status_label": "Pending Review",
    "dkim": {
      "public": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQ...",
      "selector": "scph0722",
      "headers": "from:to:subject:date"
    }
  }
}
```

## Required DNS Records

For a basic sending domain setup, you'll need these DNS records:

| Type  | Name                    | Value                                            | Purpose             |
| ----- | ----------------------- | ------------------------------------------------ | ------------------- |
| TXT   | `{selector}._domainkey` | `v=DKIM1; k=rsa; h=sha256; p=...`                | DKIM signing        |
| TXT   | `_dmarc`                | `v=DMARC1; p=none; rua=mailto:dmarc@example.com` | DMARC policy        |
| CNAME | `@` (root domain)       | `sparkpostmail.com`                              | Domain verification |

<Note>
  The DKIM selector and public key are unique to your domain and will be provided when you add your domain. Copy them exactly as shown.
</Note>

## Domain Status

Each domain has an approval status that determines whether you can send emails:

| Status     | Description                 |
| ---------- | --------------------------- |
| `pending`  | Domain awaiting review      |
| `approved` | Domain approved for sending |
| `blocked`  | Domain blocked from sending |

DNS records are verified separately with their own status values (`valid`, `unverified`, `invalid`, `missing`, `not_applicable`).

Check domain status via API:

```bash theme={null}
curl https://app.lettr.com/api/domains/example.com \
  -H "Authorization: Bearer lttr_xxxxxxxxxxxx"
```

```json theme={null}
{
  "message": "Domain retrieved successfully.",
  "data": {
    "domain": "example.com",
    "status": "approved",
    "status_label": "Approved",
    "can_send": true,
    "cname_status": "valid",
    "dkim_status": "valid",
    "dmarc_status": "valid",
    "spf_status": "valid",
    "is_primary_domain": true,
    "tracking_domain": "links.example.com",
    "dns_provider": "cloudflare",
    "created_at": "2024-01-15T10:30:00Z",
    "updated_at": "2024-01-15T10:35:00Z"
  }
}
```

## Domain Approval

When you add a new sending domain, Lettr automatically evaluates it through a scoring system. Each domain starts at 100 points, with deductions for risk factors like very new registration, uncommon TLDs, or suspicious naming patterns. Domains scoring 50 or above are approved automatically.

The scoring evaluates:

* **Domain age** — Older, established domains score higher (2+ years is ideal)
* **Domain characteristics** — Standard TLDs and conventional naming patterns
* **Active website** — AI-powered analysis of website legitimacy and content quality

Domains meeting the approval threshold are approved within minutes. If your domain is blocked, you can request a manual review by contacting [support@lettr.com](mailto:support@lettr.com).

For full details on scoring criteria, thresholds, and tips for improving your score, see [Domain Approval Process](/learn/domains/approval).

## Learn More

<CardGroup cols={2}>
  <Card title="Sending Domains" icon="paper-plane" href="/learn/domains/sending-domains">
    Configure domains for sending emails with SPF, DKIM, and DMARC
  </Card>

  <Card title="Tracking Domains" icon="chart-line" href="/learn/domains/tracking-domains">
    Set up custom domains for click and open tracking
  </Card>

  <Card title="Inbound Domains" icon="inbox" href="/learn/domains/inbound-domains">
    Receive emails at your domain
  </Card>

  <Card title="Storage Domains" icon="hard-drive" href="/learn/domains/storage-domains">
    Host email assets on your own domain
  </Card>

  <Card title="DMARC" icon="shield" href="/learn/domains/dmarc">
    Protect your domain with DMARC policies
  </Card>

  <Card title="BIMI" icon="image" href="/learn/domains/bimi">
    Display your logo in email clients
  </Card>

  <Card title="Domain Approval" icon="check" href="/learn/domains/approval">
    How domain scoring and approval works
  </Card>

  <Card title="Domain Connect" icon="bolt" href="/learn/domains/domain-connect">
    Automatic DNS setup for Cloudflare domains
  </Card>
</CardGroup>