| Name | Type | Description | Notes |
|---|---|---|---|
| Content | string | The base64-encoded contents of the file. | |
| Type | string | The type of file being attached. | |
| Filename | string | The name of the file being attached. | |
| Disposition | string | Inline for content that can be displayed within the email, or attachment for any other files. | |
| ContentId | string | An ID for the content. |