Zimbra Server connect to google apps

Hi,
i have 20 account @copiaincolla.net on google apps platform and i would like to map this account on an internal office Zimbra Server to use our personal Zimbra server
as collaborative suite (powerful than google apps) and as Backup server (if internet go down in office google apps is always up !)

it's possible to syncronize Zimbra Server with imap protocol with Google apps server ?
or download as pop3 from google apps and send by smtp to google apps ?

tks all