I receive a lot of spam

==== Required information ====
- iRedMail version: 0.8.3 Pro
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP/MySQL
- Linux/BSD distribution name and version: Ubuntu Server 12.04 LTS
- Related log if you're reporting an issue:
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Hi,
Users receive spam (5-10 day). I would like to reduce the level of spam.
/etc/default/SpamAssassin is off.
The Regards
Thanks