Iredmail mail server locally

==== Required information ====
- iRedMail version: 0.9.0
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Linux/BSD distribution name and version: Centos 6.6
- Related log if you're reporting an issue:
====

Hello there,

1st of all thanks for the great product I can't find any easier mail server installation out there
I have a question , I need to install the mail server to work only locally on premise I don't need to send mails or relieve from the internet is that possible sorry for my bad English.

Thanks again.