Errors in Setup Local Mail Server

1.while giving user name and password , its not logging in , shows as error like this
2. while sending and receiving in Postfix and dovecot its working

For example,

[root@surya surya]# telnet surya pop3
Trying 192.168.101.27...
Connected to surya.
Escape character is '^]'.
+OK Dovecot ready.
user sk              
+OK
pass sk
+OK Logged in.
retr 1
+OK 431 octets
Return-Path: 
X-Original-To: sk
Delivered-To: sk@surya.localdomain
Received: from localhost (surya.linux.com [192.168.101.27])
	by surya.localdomain (Postfix) with ESMTP id 57E2020834
	for ; Mon, 17 Aug 2015 16:12:13 +0530 (IST)
Message-Id: <20150817104226.57E2020834@surya.localdomain>
Date: Mon, 17 Aug 2015 16:12:13 +0530 (IST)
From: sk@surya.localdomain
To: undisclosed-recipients:;

test

can u plz tell whats the error is

Two possible reasons are there to get such error:

  1. Configure your DNS correctly to resolve name resolution or
  2. Check the permission of /etc/nsswitch.conf file and set it to 644.

Thanks @ravisaive , ya the problem is in the DNS only, mail server is working now.
still come problems exists since there are some problems in DNS, can u send the link for to configure DNS server in cent os 6.5

Here is the article the describes how to setup caching only DNS server on CentOS 6.5, I think this is what you looking for…

http://www.tecmint.com/install-caching-only-dns-server-in-centos/