index | The index of the attachment, if it is sent along with other attachments. Index 0 is the first attachment. |
id | A unique identifier for the attachment content. It corresponds to the sub-part Content ID of the MIME/Multipart subpart in which this attachment was sent. |
type | The Content-Type of this attachment. |
description | A description of the attachment. |
disposition | The MIME Multipart Content-Disposition of this attachment. |