Greetings
I have just set up an Exchange hybrid environment running Exchange Server 2013 CU11 and Office 365.
I'm running into a problem where mailboxes in the cloud cannot see free/busy information for user mailboxes on the on prem Exchange server.
Testing shows that:
Bi-directional mailflow works.
Users on prem can see free/busy for on prem and cloud mailboxes
Cloud mailboxes can see free/busy for cloud mailboxes but not on prem mailboxes
The free busy test at https://www.testconnectivity.microsoft.com is successful for a prem mailbox user.
Running that test as a cloud user fails at this step
Attempting to send an Autodiscover POST request to potential Autodiscover URLs. - error code 500, the e-mail address can't be found
Autodiscover is pointed at the on prem exchange server.
Any assistance for how to resolve this issue would be appreciated.