I have setup a Qtek A9100 using this steps:
Launch Active Sync Menu -> Configure Server
Setup the following: Server Address: (FQDN) ( ) Choose SSL Unselect this option
User Name: user Password: zimbrapassword Domain:domain.com
Select the items to be syncronized, leaving Task out because Zimbra does not handled this.
Then you can modify settings for mail and calendar at your will. It worked fine.
It's important that you have the server cert installed on the smartphone, if you dont, proceed to do so.