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As of now, we are having Exchange Server and Zimbra Server.
We need to sync all contacts, calendars etc from Zimbra to Exchange or Exchange to Zimbra.
We are also looking out for solution to built up an OpenLDAP Server (new machine) from where there will be automatic syncing of addresses, calendars for both Exchange (Windows 2003) and Zimbra.
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Zimbra Sync with Exchange Server 
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