View WHOIS and DNS records on macOS
There is no need to visit shady ad dumpster fires if you are on macOS, the commands are already built-in macOS.
Get info about the owner with whois and nslookup
$ whois mydomain.com
View DNS records
$ nslookup mydomain.com
$ nslookup -q=mx mydomain.com
dig is available on macOS we can use this for more detailed answers.
$ dig mydomain.com
$ dig -t mx mydomain.com