I hope someone can help with a problem I've been struggling with for sometime now. I'll do my best to remember everything that's been tried and tested so far but I'll try to stick to the main issue as much as possible. In short, the problem I have is that I cannot add the Office 365 forest to my Exchange environment.
Having spent some time on the issue, I still think the connection is being blocked by our firewall (x2 ISA Server 2006) however, through all the work I have done, the rules look to be setup correctly to me.
So to get to the specific error, when I try to add the Office 365 forest, I get the error shown below. I can sign into the Office 365 portal with the same credentials, on the same machine and the Directory Sync tool (on another server) also works fine with the same credentials. If anyone has any specific questions about our setup, I should be able to answer them.
Thanks in advance.