metadata
metadata: {
aborted_at?: string;
bounced_at?: string;
campaign_api_id: string;
delivered_at?: string;
enqueued_at?: string;
executed_at?: string;
external_send_id: string;
processed_at?: string;
reason?: string;
received_at?: string;
sent_at?: string;
}
Postback body for sending transactional email via API-triggered delivery.
https://www.braze.com/docs/api/endpoints/messaging/send_messages/post_send_transactional_message/#postback-body