I'm using Zimbra Server 7.1.2 GA 3268 and I tried to upgrade my ZCO from 6 to x86. No problem during the upgrade, until I start outlook.

The error message tell me that outlook can't connect to the server because he can't verify the server's identity. We use a free certificate on the server, and don't want to buy one yet. Is there a way to use ZCO with https without a verified certificate ?