This seems to be a common theme for cpanel servers.
Please check your nameservers with this dnsreport.com. If you get a red box that says Open DNS Servers, please fix it quickly by using the following instructions.
Edit /etc/named.conf and add this line after the directory line:
allow-recursion { 127.0.0.1; 123.123.123.123; 456.456.456.456; };
Replace test IPs with yours.
