Short answer: poll the mail transport from a background collector, store immutable receipts under your own message ID, and let the Node. js dashboard read a local projection of sent , delivered , and bounced . Polling the transport from each browser tab looks simpler, but it couples user traffic...
Source: [Dev.to](https://dev.to/brockfletcher1438/message-id-receipts-for-nodejs-transactional-email-delivered-or-bounced-1pje)