Zimbra installations hanging

Hello all,

I am new to the site and to linux! I am trying to setup a Centos server with emailing capabilities using virtualbox for learning purposes. I wan to set up Zimbra with split DNS to be able to send and receive emails from other domains, I already setup MX records with dyn dns.
I started the installation and its hanging for almost 4 hours now in the bellow screen:

DNS ERROR resolving MX for mail.alep11.com
It is suggested that the domain name have an MX record configured in DNS
Change domain name? [Yes] yes
Create domain: [mail.alep11.com]

What did I do wrong?
----------------------------------------------------------------------------------------
#cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
192.168.1.20 mail.alep11.com mail
-----------------------------------------------------------------------------------------------------------
#cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=mail.alep11.com
GATEWAY=192.168.1.1
-----------------------------------------------------------------------------------------------------------

# cat /etc/resolv.conf
# Generated by NetworkManager
search alep11.com
nameserver 192.168.1.20
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
--------------------------------------------------------------------------------------------------------------------
#cat /etc/named.conf
//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//

options {
listen-on port 53 { 127.0.0.1;192.168.1.20; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { localhost; };
recursion yes;

dnssec-enable yes;
dnssec-validation yes;
dnssec-lookaside auto;

/* Path to ISC DLV key */
bindkeys-file "/etc/named.iscdlv.key";

managed-keys-directory "/var/named/dynamic";
};

logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};

zone "." IN {
type hint;
file "named.ca";
};

zone "alep11.com" {
type master;
file "mail.alep11.com";
};

zone "1.168.192.in-addr.arpa" IN {
type master;
file "192.168.1.zone";
};

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";
-------------------------------------------------------------------------------------------------------------------------------------

#cat /var/named/192.168.1.zone;
; Addresses and other host information.
;
@ IN SOA alep11.com. hostmaster.alep11.com. (
2013042301 ; Serial
43200 ; Refresh
3600 ; Retry
3600000 ; Expire
2592000 ) ; Minimum

1.168.192.in-addr.arpa. IN NS centos.alep11.com.

20.1.168.192.in-addr.arpa. IN PTR mail.alep11.com.
20.1.168.192.in-addr.arpa. IN PTR ns1.alep11.com.
[root@mail pedro]# cat /var/named/192.168.1.zone
;
; Addresses and other host information.
;
@ IN SOA alep11.com. hostmaster.alep11.com. (
2013042301 ; Serial
43200 ; Refresh
3600 ; Retry
3600000 ; Expire
2592000 ) ; Minimum

1.168.192.in-addr.arpa. IN NS centos.alep11.com.

20.1.168.192.in-addr.arpa. IN PTR mail.alep11.com.
20.1.168.192.in-addr.arpa. IN PTR ns1.alep11.com.
-------------------------------------------------------------------------------------------------------------------------

#cat /var/named/mail.alep11.com
;
; Addresses and other host information.
;
@ IN SOA alep11.com. hostmaster.alep11.com. (
2013042301 ; Serial
43200 ; Refresh
3600 ; Retry
3600000 ; Expire
2592000 ) ; Minimum

; Define the nameservers and the mail servers

IN NS ns1.alep11.com.
IN A 192.168.1.20
IN MX 10 mail.alep11.com.

centos IN A 192.168.1.20
mail IN A 192.168.1.20
ns1 IN A 192.168.1.20
------------------------------------------------------------------------------------------------------------------

#cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=08:00:27:3A:D4:72
TYPE=Ethernet
UUID=bbc8d623-6cde-4b07-8059-e4c2ebf7ff0b
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
IPADDR=192.168.1.20
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
DOMAIN="alep11.com"

Thanks in advance.