DigitalOcean is solid and cheap.

With my one user gsuite I setup a secondary domain in it so lemmy sends from no-reply@lemmy.gregw.us, not my main address, but lemmy still authenticates using my main address.

Curious what the final cause of death will be.

Another vote for Immich. It does a good job.

I set up a smtp relay with gsuite for outgoing mail but don't think it is ideal; it is tied to my user. It was just expedient rather than preferred.

Totally looking forward to the answers here.