This is a really cool concept. The mailbox at its base is just a specific type of data store.

I haven't looked at the code. How are you dealing with projects scattered across different environments, are you routing those notifications yourself back to a central imap store, or do you have several different stores?

I kept setting up a sending domain + SPF/DKIM/DMARC + SES/SendGrid just to email myself app notifications (contact forms, cron failures). But I wasn't trying to reach anyone else's inbox, just my own.

inbox-beam skips sending entirely: it uses the IMAP APPEND command to write the message straight into your mailbox. No SMTP, no deliverability. It shows up unread and searchable.

It's explicitly NOT email delivery — it only writes to a mailbox you control, so it can't reach third parties, and keeps no send log. For that you still want real SMTP. npm: https://www.npmjs.com/package/inbox-beam