I'm quite happy with Migadu for own domain use. I have a dozen that are unlikely to receive email but good to be able to receive them nonethelrss - migadu is great for that as you can add as many domains as you want.
Calendar feature is sorely missing though it seems this service also doesn't have it. I guess calendar is a pain to set up/troubleshoot timezone issues, etc
I think they have calendar the show how to set it up here, they just dont have a GUI for it https://www.migadu.com/guides/thunderbird/
I'm looking forward to them deploying 'Alps' their new UI I've been using it on my self-hosted mail and its pretty sweet.