Disable spamassassin and clamav and gray/white list

==== Required information ====
- iRedMail version:  iRedMail-0.8.7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Ubuntu 14
- Related log if you're reporting an issue:
====
Hi,
I want to disable disable spamassassin and clamav and gray/white list, because my mail server in internal.
The external mail server has those features. Please help.