IMPORTANT: Do not ignore this email. Your hostname (yourhostname.com) could not be resolved to an IP address. This means that /etc/hosts is not set up correctly, and/or there is no dns entry for yourhostname.com. Please be sure that the contents of /etc/hosts are configured correctly, and also that there is a correct 'A' entry for the domain in the zone file. Some or all of these problems can be caused by /etc/resolv.conf being setup incorrectly. Please check that file if you believe everything else is correct. You may be able to automatically correct this problem by using the 'Add an A entry for your hostname' option under 'Dns Functions' in your Web Host Manager.
If you are using cPanel/WHM & getting this email everyday, it means that your IP configuration is not done correctly. But maybe some of you purposely done this due to security reason. Due to this, you may not want to receive this email everyday.
To disable this login to WHM. Go to
Server Contacts → Alert Priority Assignment → IP Address DNS Check → Set Priority to Disabled → Save