This method retrieves an attachment based on the attachment ID passed. A session key must be submitted via the X-Session-Key header. The request body should be left empty. The attachment ID of the message you'd like to retrieve must be passed in the URL of this method. A successful transaction will receive a 200 status code.
The X-Session-Key header is missing. || Bad session key. || Session key expired. || Could not parse the attachment ID into an integer. || You do not have access to attachment with id [AttachmentId]. || The message has been deleted from the Inbox and is no longer available. || This message has been deleted from Track Sent and is no longer available. || An error has occurred at [DateTime] please check the server logs for details.