My recommendation for everyone is to use Fastmail and a custom domain.
Fastmail is extremely reliable, and since they charge money they also offer customer support. A few years ago I lost a lot of emails due to a client bug, and Fastmail support was very helpful recovering them from backup.
Use a custom domain so you can change providers in the future so you're not locked into your provider and can change if you aren't happy with them anymore.
My recommendation for everyone is to use Fastmail and a custom domain.
Fastmail is extremely reliable, and since they charge money they also offer customer support. A few years ago I lost a lot of emails due to a client bug, and Fastmail support was very helpful recovering them from backup.
Use a custom domain so you can change providers in the future so you're not locked into your provider and can change if you aren't happy with them anymore.