Once you have installed the Outlook Connector version number 7.x, you can update to a newer version of the program.
If you haven’t installed the Outlook Connector yet, follow the guide Synchronizing with Outlook [PRO]
Go to the Zimbra > Check for updates (top right corner).
If there is a new version to update you can do so by clicking Upgrade in the popup window.
Go to Help > Check for updates. If there is a new version to update you can do so by clicking Upgrade.