I have the strangest problem with one user only. Calendar sync between Outlook (184.108.40.20647) and webmail, Samsung Android does not work.
Calendar sync works between Samsung Android and webmail AND between two computers running Outlook 2010 with 220.127.116.1147 connector but not between Outlook and webmail/Android. Just like hes ot two calendars running at the same account.
Zimbra Webmail<-->ZCS<-->Android OK!
Zimbra Webmail<-->ZCS<-->Outlook NOT OK!
Android<-->ZCS<-->Outlook NOT OK!