We will be upgrading our Zimbra infrastructure to 5.0.18 this weekend.

ZCS 5.0.18 contains many important enhancements and bug fixes, including:

• Critical security updates (Already patched in our setup as soon as the security update was published.)
• Outlook 2007 rules are now run automatically. If an Outlook rule and a Zimbra rule act on the same message, the Outlook rule will run first. Note that Outlook 2007 has a local rule called Clear Categories on Mail that is turned on by default. If this rule is enabled, it will clear categories on messages. This rule should be disabled. To disable, in Outlook, go to Tools->Rules and Alerts…, and uncheck Clear categories on mail.
• Out-of-office replies can now be set in Outlook This feature is accessed from Tools->Out of Office Assistant.
• Appointment reminder pop-ups now work as expected

The maintenance window is from 8pm to 10pm PDT Friday night, expected downtime is 30 minutes or less.