Have you considered Migadu? I don't have shares there, just a very happy customer :-).

I did. Their 20 out/day (soft limit) had me concerned. While many weeks I might send less than 7 emails I still feel uncomfortable with those limits.

	▲	palata 3 days ago \| parent [-]
		As you said, those are soft limits, i.e. there is a human on the other side. If they feel like you use more than you should, they will talk to you instead of kicking you out.