My previous post just showed how to enable the two different scoring actions - delivery and discarding. It is actually doubtful if the 2 levels are useful to your wishes but instead of just discarding the high scoring spam you could also send this to a system-wide quarantine mail box, or if the proper syntax is available, to the individual users junk mail box.
The variable to set for final destiny of killed spam mail is...
$spam
quarantineto =
Off-hand, I don't know how you would set the tagged mail to go to individual junk mail folders and separately discard or send kill_level mail to a system wide quarantine box. There is only the one spam
quarantineto option and this gets triggered at the kill_level.
To get the 3 levels you would need to upgrade amavisd - see pdf download at
http://osx.topicdesk.com for instructions.
-david