iRedmail - not able send mail from the same local network were the server connected

[Ashoksmclain]

hi
we are not able to send from our local network connected clients (that is the same network were the iRedMail server in connected) but we are able to send mail from outside our local network (that is from different location)

please let us what mistake we have done i am attaching the mail log fail for reference

the information about our server is:
- iRedMail version: 0.8.3
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Linux/BSD distribution name and version: Ubuntu Server 12.04 LTS
- Related log if you're reporting an issue: mail.log