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

# Update Mail Settings

> Update your organization's mail settings

Update one or more organization-level mail settings. This is a partial update — only the fields you include in the request body are changed, and any omitted fields are left untouched. Pass `null` for a field to clear it back to its default.

## Body Parameters

| Field                          | Type           | Description                                                 |
| ------------------------------ | -------------- | ----------------------------------------------------------- |
| `default_postcard_size`        | string \| null | Default postcard size: `4x6`, `6x9`, or `6x11`.             |
| `default_sender_name`          | string \| null | Sender name pre-filled on new campaigns (max 255 chars).    |
| `contact_frequency_limit_days` | number \| null | Minimum days between mailings to the same contact (0–3650). |
| `default_qr_code_url`          | string \| null | Default QR code destination URL. Must be a valid URL.       |
| `default_signature_image_url`  | string \| null | Default signature image URL. Must be a valid URL.           |

<RequestExample>
  ```bash cURL theme={null}
  curl -X PATCH https://api.v2.dealmachine.com/v1/mail/settings \
    -H "Authorization: Bearer dm_sk_live_xxx" \
    -H "Content-Type: application/json" \
    -d '{
      "default_postcard_size": "6x9",
      "contact_frequency_limit_days": 30
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={null}
  {
    "data": {
      "default_postcard_size": "6x9",
      "default_sender_name": "Acme Real Estate",
      "contact_frequency_limit_days": 30,
      "default_qr_code_url": "https://acme.com/offer",
      "default_signature_image_url": "https://atlas.s3.amazonaws.com/signatures/abc.png"
    }
  }
  ```
</ResponseExample>