Download DNS list from https://public-dns.info/, which will be a file like below:
ip_address,name,as_number,as_org,country_code,city,version,error,dnssec,reliability,checked_at,created_at
8.8.8.8,dns.google.,15169,GOOGLE,US,,,,true,1.00,2022-04-17T08:03:50Z,2020-07-16T14:19:04Z
then, run the command below to run tests
./test_dns.sh -f us.csv -d gordarg.com -n 5 -r MX