Soverin is a Dutch email provider with a focus on privacy and custom domains. The standard price of the service even contains one domain. Using a personal domain reduces the vendor lockin of the email provider.
Soverin only offers one plan which costs 3,25€/month and includes a domain. If you already have a domain you get a discount. It's possible to buy extra mailboxes for a cheaper price. (6€/year)
Read more about the pricing of the service here
Soverin is hosted only in the EU.
The servers are powered by electricity from sustainable sources.