transfer emails to new email server

==== Required information ====
- iRedMail version: 0.8.7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Ubuntu 14.04
- Related log if you're reporting an issue:
====

Hi I have a new server and I want to do the following.. I want to transfer a domain pointed to an email server ( iRedMail ) to a new server with same iRedMail version etc. the only problem I encounter is the emails I have received. Is there a nice easy way to transfer them into my new server?

Thanks in advance