What Does Host Or Domain Name Not Found Mean. Apple may provide or recommend responses as a possible solution based on the information provided. It might be legal to not have an A record but is a good idea too have an A record for the relay.
NXDOMAIN can also take place due to the network or DNS server problem. Behind each domain name there is an address of the web hosting service storing the websites files. In the GUI for a Microsoft Windows Server DNS Service this is or at least has been for a long time called Same as parent folder.
I am an administrator of a Exchange Server who is seeing this same problem.
When facing issues with your website or email its vital to understand how to check DNS for your domain name. In addition computers can be found by others through the hostname which enables data exchange within a network for example. It might be legal to not have an A record but is a good idea too have an A record for the relay. I am an administrator of a Exchange Server who is seeing this same problem.