==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.9
- Deployed with iRedMail Easy or the downloadable installer? no
- Linux/BSD distribution name and version: CentOS 7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? no
====

Hi. I want to store spam messages on filesystem, not database or both. I configured the following options in Amavis:
$QUARANTINEDIR = '/var/lib/amavis/quarantine';     # -Q
$final_spam_destiny = D_DISCARD;
$spam_quarantine_method = 'local:spam/spam-%b-%i-%n';
$spam_quarantine_to = 'spam-quarantine';

and set spam_lover='N' in amavisd database. Still all spam messages are stored in mysql, '/var/lib/amavis/quarantine is empty.