==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.5-1
- Linux/BSD distribution name and version: CentOS 7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- Related log if you're reporting an issue:
====

I am using exchange server for my emails but I want to move to iRedMail solution.
Some of my mailboxes (.pst files) are more that 15gb and I am thinking using imapsync to migrate my emails.
should I stay with exchange or iRedMail (all software included) can handle it?