When syncing with Outlook plugin, how do I sync the same contacts with multiple users?

When syncing with Outlook plugin, how do I sync the same contacts with multiple users?

All the contacts in our Zoho CRM database were created by user X. When I log in as user Y using the Outlook plugin and sync contacts, it reports that there are no contacts to sync. When I log in as user X, it happily syncs all the contacts. How do I sync all the contacts with all the users?

Thanks!