Domain Name System (DNS) is an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they are easier for users to remember. The Internet is based on IP addresses. Each time you use a domain name, therefore, a DNS must translate the name into the corresponding IP address. For example, the domain name www.example.com might translate to 198.105.232.4.
CallPilot desktop messaging clients use domain name resolution. If your environment does not have a DNS, you have two options:
Resolve domain names using a HOSTS file.
Configure desktop messaging e-mail clients with the IP address of the CallPilot server if you do not want to use a HOSTS file.
If your environment does include a DNS, you should verify the fully qualified domain name (FQDN). For information about setting the FQDN, see Defining the fully qualified domain name.