If your mail is extremely low volume, you might like Migadu's low cost plans. They charge by number of messages in/out rather than per domain or something. It's been handy for me for a few lightly used domains including resurrecting one that the previous owner had let expire and then suddenly needed.

I've kind of been waiting for an excuse to make that move for my solo freelance business. It's probably not enough of a price difference to push me (+$24/year) but it really irks me to be forced into subsidizing this garbage.

I occasionally do office document stuff which Workspace had been nice for and I can't be bothered with Windows/Office so maybe time to revisit LibreOffice or maybe go full on Emacs.