FastMail custom domain with Cloudflare DNS
Setting up FastMail with a custom domain is easy. However, there is one pitfall when using CloudFlare:
Some services require additional CNAME records for DKIM verification. CNAME DKIM records should be gray clouded; otherwise, the record value won’t be available and verification will fail.
So it’s important to “click the cloud next to each record” to turn CloudFlare off (grey icon):