To be clear, we need two independent things:

• team members receiving emails to a team's nixos.org address (should be somewhat easy to keep up to date who's in the recipient list, ideally eventually auto-synced with whatever mechanism is available for managing teams)
• reliably mailing to numerous contacts from the nixos.org address

dgrig, you've correctly identified the state of things. The summary at the top of https://github.com/NixOS/infra/issues/485 is accurate. We need to set up some alerts for the mailserver. I just haven't taken the time to familiarize myself with prometheus and the blackbox alerting we have set up on pluto. I don't think there's a lot of work remaining there.

Here's an idea that feels low risk: we could set up this new mailserver to send emails alongside our existing improvmx account. That would let us start to test out this arrangment without breaking any existing send accounts.