I've been an administrator of a postfix/amavisd-new/spamassassin setup for years so I'm very aware of how little spam is caught under a default install of these programs. I'm *assuming* that Zimbra, since it's based off of these core technologies, would have a similar dismal spam blocking ratio (no offense to Zimbra, I love the program). I'm looking at porting over my existing spamassassin config + razor2 + DCC + a few RBL's + whitelist/blacklist to a Zimbra installation. My only concern is the fact that several places (Improving Anti-spam system - Zimbra :: Wiki & http://www.zimbra.com/forums/install...tabases-3.html for an older version) mention that upgrades have the potential of wiping out the custom spam fighting rules when updating, even from one minor version to the next. I would like to hear from users with a similar, customized spam system on the pitfalls, workarounds, and tips for making the Zimbra upgrade process easier and more manageable. Thanks in advance.