OpenDKIM with iRedMail

==== Required information ====
- iRedMail version: iRedMail-0.9.0
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Linux/BSD distribution name and version: CentOS 6.6
- Related log if you're reporting an issue:
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Hi, any idea how do I go about integrating OpenDKIM with iRedMail? Thanks