I'm trying to configure Free/Busy Interop on our test Zimbra 8.0 server. When I click on the "Check the Settings" button, I get the check.AUTH_FAILED message. Zimbra users can't see Exchange users freebusy info and vice-versa. Followed the info found at the following links with no success:

• Exchange 2010 Free/Busy Interop - Zimbra :: Wiki
• Setting Up Free Busy Interop with Exchange 2010 - Zimbra :: Wiki
• Troubleshooting Exchange Freebusy Interop - Zimbra :: Wiki

As far as the certificate is concerned, I exported the self-signed certificate from the exchange server and importing it successfully on the Zimbra server.

Anyone have the same problem and found a way to make it work? Any help is appreciated thank you.