I'll try and correct.
The OP did not have require SSL checked. And if SSL is NOT checked, then it will work as I orginally described.
It looks like you have checked SSL, based on the logs, correct?
Assuming that is the case, if you check SSL you must:
- Change the port to 636 - this is the cause of server not available message
- Export the Root Certificate for your AD domain from the domain controller (not the DC's cert) and upload to IMC
If the wrong cert is uploaded the message will change to wrong authentication file or something like that.
Hopefully that helps - I have verified both SSL and non SSL configuration on my system, so if you are still having issues, there is some other problem.