How do I stop and start amavisd-new?

The proper way to stop and start amavisd on OS X Server 10.5.x/10.4.x is to issue:

 sudo /bin/launchctl unload /System/Library/LaunchDaemons/org.amavis.amavisd.plist
sudo /bin/launchctl load /System/Library/LaunchDaemons/org.amavis.amavisd.plist