Enable quarantining http://www.iredmail.org/wiki/index.php? … ining.SPAM
We careful though, in less than 12 hours we had over 50,000 spam caught in there. We eventually had to stop storing the spam set amavis to outright drop the spam messages.
Depending on your setting amavis will also try to quarantine to /var/spool/amavisd/quarantine/