My favorite domain registar is https://www.inwx.com/en https://www.inwx.com/en. They are very cheap for .de domains which I mostly use, they have an API and the

My favorite domain registar is https://www.inwx.com/en https://www.inwx.com/en. They are very cheap for .de domains which I mostly use, they have an API and they offer dyndns as well as a mail service that is hosted by them (although that's a bit pricey in my opinion.