I can’t recommend Migadu. I used them for a year, and I spent many hours dealing with delivery issues and somewhat frequent unannounced outages/upgrades which go unreported. Spam filtering is generally broken and ignores whitelists. They tend to respond to about 50% of support emails, the last one being rather petty when I left the service.
I should have seen the yearly plan fee as a sunk cost and moved on sooner. Hope this helps someone else.
If you're going with a smaller email provider, you kind of have to know what you're getting.
Keep in mind that several large email providers blacklist competitors by default and _literally charge an extortion fee_ to get off the blacklist. Migadu's issue is that they refuse to pay it.
I really wish Migadu had a very basic standards compliant contacts and calendar system to make it easier to switch away from the big suppliers. I respect the absolute focus on email, but unfortunately there is no equivalent style of provider for these services. There are some providers but they're expensive.
I should have seen the yearly plan fee as a sunk cost and moved on sooner. Hope this helps someone else.