If IPCONFIG or WINIPCFG displays an IP address in the DNS Servers box (as shown in the illustration below), the client computer is configured to resolve host names through the DNS.
The next step is to verify that the DNS server is available. At the command prompt, ping the DNS IP address.
Ping Fails If the ping fails, the client computer is configured for a DNS server that is down or otherwise not available. DNS has to be either disabled or configured for a DNS server that is available at all times.
Ping Succeeds If the ping succeeds the DNS server is available but does not resolve the host name in question. Provided that the DNS server is configured properly, the Microsoft Exchange Server computer name and IP address have to be added to the DNS database. After this is done, pinging the Microsoft Exchange Server computer name should resolve to an IP address by the DNS server, enabling faster startup times of Microsoft Outlook.