1. We can download the Zimbra desktop latest version from below given link
2. For install Zimbra desktop, please follow below given KB Link
3. After installing Zimbra account, now for synchronize the address book. Please follow the below given steps.
a. Select Find Shares option from the left panel.
b. Select Global Address List option.
c. Search the galsync email id from server to connect the addressbook.
d. Check the internalGAL option. And select ADD to connect and synchronize.
4. Now we can find all contacts have synchronized on addressbook and the synchronization will continue time to time.