I’m using Purelymail with my own domain for email hosting. It’s been working very well for me. It supports CalDAV and CardDAV for calendar and contacts. It’s US based though.

I would recommend paying for an email hosting service. As long as you use your own domain, you can switch email providers and keep your email addresses. If you have a static IPv4 address, you can host your own inbound email and just use the hosting service for outbound.