I've configured Google Calendar to sync its Calendar with my Zimbra's .ical URL.

Although, this is not a two way sync. I want Google Calendar to write into Zimbra as well.

The reason of this, is that I have ZOS 5.0.13 and I want my blackberry through google's sync application to write into Google Calendar and then into Zimbra.

Since, I'm not a Zimbra Network user, I cannot sync directly OTA with my blackberry into Zimbra's Calendar.

Can I enable two way sync from Google Calendar to Zimbra OpenSource?