Dear Sombath,
I moved your post form general to CRM. Since its a CRM related problem. In future please do your posts under the correct product. Thanks.
For your problem what i see is the outlook client setup may not be able to resolve your CRM server name. Try the following and see if they work.
1. Use the IP address of the server instead of the name
2. Use the full FQDN of your CRM server - servername@domain.com/crmurl
3. Use nslookup to see if your CRM server name resolved to the IP address.
Make sure that u can access the webclinet from this computer without a problem before u setup outlook client. And make sure CRM url is added to the local intranet sites
Hope this helps you
Cheers!
Sampath