You might have definitely heard of DNS. It is a domain name system and this is specified with different IP address through Dns lookup. These days’ technicians are also making use of reverse dns lookup as well. This is easily allied with domain name systems and this is used for prevention of spasm. This will be more of complicated even this is used for easy determination of whether emails are coming through domain names that are designated in message headers. In fact, it is a bit of complicated and a time consuming process. You can understand the entire process of DNS easily.