I have in the past synchronised Zimbra NE with a bunch of mobile devices (htc, iphone..) without any problem.
Recently a new client came on board with a Blackberry (No BES server) and an iMac. No OTA sync with Blackberry.
My first setup was to use Blackberry Desktop in order to sync with the iCal and address book.
Then I installed the iSync connector in order to sync the ical and the address book with zimbra.
The test results where almost fine :
Zimbra Calendar--> iMac iCal --> Blackberry Calendar= OK
Zimbra Contacts-->iMac address Book --> Blackberry Address book= OK
Reverse side :
Blackberry address Book--> iMac Address Book ---> Zimbra Contacts = OK
Blackberry Calendar--> iMac Ical --> Zimbra Calendar = NOT OK AT ALL
Because the Blackberry Desktop does sync calendar events with the 'home' ord 'work' calendars in iCal, none of them are synced with Zimbra.
I just want to share the 20 mn setup I have put in place that works properly :
You need to build a webdav server on one of your web servers.
1 - Build a webDav server.
2- Publish the calendar on wich you see the blackberry events appearing on ical. When you publish on iCal, choose the 'private server' option.
3- On the Zimbra client account add a calendar and check sync with the remote calendar.
I do not know if it is mandatory for this feature, but I checked in preferences > Calendar :
[x] Enable delegation for Apple iCal CalDAV client
Thanks fo you comments if you have faced the same issues on syncing a Blackberry without a BES.( I know that there are products like astraSync...)