[vinaysatwe]

here are the answers for the commands:
[root@mail ~]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhost6
192.168.1.5 mail.mydomain.com mail


[root@mail ~]# cat /etc/resolv.conf
search mydomain.com
nameserver localhost
nameserver 202.54.10.2
nameserver 202.54.29.5


[root@mail ~]# dig mydomain.com mx

; <<>> DiG 9.3.4-P1 <<>> mydomain.com mx
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11650
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;mydomain.com. IN MX

;; ANSWER SECTION:
mydomain.com. 8628 IN MX 10 61.xx.76.xx.

;; Query time: 24 msec
;; SERVER: 202.54.10.2#53(202.54.10.2)
;; WHEN: Thu Jul 2 15:52:10 2009
;; MSG SIZE rcvd: 64


[root@mail ~]# dig mydomain.com any

; <<>> DiG 9.3.4-P1 <<>> mydomain.com any
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46209
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;mydomain.com. IN ANY

;; ANSWER SECTION:
mydomain.com. 3665 IN NS ns1.net4india.com.
mydomain.com. 3665 IN NS ns2.net4india.com.
mydomain.com. 8318 IN MX 10 61.xx.76.xx.
mydomain.com. 3665 IN A 202.xx.129.xx

;; Query time: 31 msec
;; SERVER: 202.54.10.2#53(202.54.10.2)
;; WHEN: Thu Jul 2 15:57:20 2009
;; MSG SIZE rcvd: 126

[root@mail ~]# host mail.mydomain.com
mail.mydomain.com has address 61.xx.76.xx

thanks friends