Not Receiving any emails

Hi
Today i installed iredmail on centos6.4, now i can send emails out but not able to receive any emails.
i can telnet my mail server on port 25, 110, 143 from out side. what can be the issue, can you please help?
my hosts file looks like this:

[root@xxxxail01 mail01]# cat /etc/hosts
#127.0.0.1  localhost localhost.localdomain localhost4 localhost4.localdomain4
#::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.5.11 xxxxil01.xxxxxsystems.com  mail01 xxxx-mail01

thanks