I have been testing Zimbra Open Source Edition for over a month now, and it does not appear that the Trashed and Spam Message Lifetime settings are working. I have the Trashed Message Lifetime set to 30 days (default) and have lowered the Spam Message Lifetime to 15 days. As far as I can tell no messages have been purged from either folder automatically.

Is there something else that I need to run to purge these messages?