Working with a new Exchange 2007 to Office 365 migration we experienced an issue with free busy between the two messaging platforms. Mailboxes on Office 365 could see free busy for Office 365 and Exchange 2007 could see free busy on Exchange 2007. However, Office 365 could not see free busy for Exchange 2007 and vice versa. We had configured ADFS, DirSync and the Hybrid Wizard for our Exchange 2013 server which would serve as the AutoDiscover connection between the two. We confirmed that DNS was correct, we confirmed that the Hybrid wizard did not generate any errors. We then began using Microsoft’s troubleshooting for Free Busy in a Hybrid environment. Our troubleshooting steps were as follows:
- Replicate the issue in Outlook and OWA for both environments. Confirmed that free busy did not work with either client for either environment.
- Verify software is correctly installed on the workstation – all Windows and Office updates.
- Used the website https://www.testexchangeconnectivity.com to see if there was a configuration issue and the test worked as expected.
- Connected to Office 365 via PowerShell and ran Get-OrganizationRelationship -Identity “Exchange Online to On Premises Organization Relationship” | FL – reviewed the DomainName value and it was set with the correct FQDN for the on-prem domain. At this point we did not realize this was incorrect, so we continued on thinking we were OK.
- We then reviewed the logs located on the Hybrid server – %SystemDrive%\inetpub\logs\LogFiles\W3SVC1 folder, opened the latest log file and searched for “Autodiscover”. We found entries for AutoDiscover.
- Next, we searched the same logs for “exchange.asmx/wssecurity”. This we could not find in the log files. This was our first clue as to the issue.
- Microsoft’s own troubleshooting guide says to check your Firewall, but this was not our issue because we tested AutoDiscover externally already. However, we did confirm that the firewall rules/NAT were correctly configured.
- We then re-ran the get-organizationrelationship command to check various values for correct information – DomainNames, TargetSharingEpr and TargetAutodiscoverEpr. The TargetAudiscoverEpr was populated correctly with https:///autodiscover/autodiscover.svc/WSSecurity. The TargetSharingEpr was blank which is correct for Exchange 2007. IF we had Exchange 2003, then this would need to be populated.
The fix was that the Office 365 domain of .onmicrosoft.com was missing. This was added back with set-OrganizationRelationship -DomainNames ,”. We forced replication from DirSync. Then we waited 30 min.
Tested Outlook and OWA we confirmed that Free-Busy was now functional from both sides. The client could now go forward with their pilot.
Exchange 2003 requires TargetSharingRpe and not Exchange 2007.
Setting TargetSharingEpr to $null – This is used to allow the free/busy between the systems to use AutoDiscover to find the information. This could be useful if you need to circumvent AutoDiscover for Free Busy processing.