Adding IPTables, Fail2ban

==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.2
- Linux/BSD distribution name and version: Debian 8.2 x64
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MariaDB
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? no
- Related log if you're reporting an issue:  no log
====

Is it possible to add the IPTables and Fail2Ban on an already installed iRedMail server? If yes, how can I do that?

Thanks.