My domain registrar is crazydomains.co.nz, because I wanted to buy a cheap *.geek.nz domain name. My authoritative DNS provider is cloudflare.com, with CrazyDomains configured to point to CloudFlare for my DNS. I also have namecheap.com as a temporary email server for my domain, with the MX entries in my CloudFlare account pointing to NameCheap’s mx1.privateemail.com and mx2.privateemail.com temporarily until I get my Yunohost installation up and running fully, then I’ll cut over to using Yunohost for email as well, and get rid of NameCheap. At that point I will need to change my MX entries in CloudFlare to get my mail working directly with Yunohost.