We are evaluating the 3.2 beta 2 release of Zimbra running on Fedora Core 5. This is to replace a home grown mail system based on Postfix, Courier-IMAP, MySQL, SpamAssassin, ClamAV, Amavisd-new, and SquirrelMail. We host about 500 users in 30 domains now and administer the domains/users with postfix.admin.
We use a nice little plugin for SquirrelMail that allows each user to control their own SpamAssassin settings for white/blacklist and tag/kill thresholds. The options are stored in MySQL and telling SpamAssassin to look for those settings in the database is simple. Most people don't make changes and are happy with the built-in defaults, but having a solution for those experienced (demanding) users has been very helpful.
Are such per user SpamAssassin preferences possible in Zimbra?
I've looked around and only see references to server-wide white list entries. At a minimum I need domain-level settings for white/blacklists, but personal settings would be better.