iCloud Mail has DNS misconfigured?

Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address. Some companies such as AOL will reject any message sent from a server without rDNS, so you must ensure that you have one. You cannot associate more than one domain name with a single IP address. Your IP address 57.103.88.93 is associated with the domain p-east1-cluster7-host9-snip4-10.eps.apple.com. Nevertheless your message appears to be sent from p00-icloudmta-asmtp-us-central-1k-100-percent-10.p00-icloudmta-asmtp-vip.icloud-mail-production.svc.kube.us-central-1k.k8s.cloud.apple.com. You may want to change your pointer (PTR type) DNS record and the host name of your server to the same value. ... Read full article.