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?

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