- Cause 1: The External Schedule+ Free Busy public folder for Microsoft Exchange Server 2003 Support was not installed. In this case, the "OU=EXTERNAL (FYDIBOHF25SPDLT)" public folder is missing from the public folder hierarchy.
- Cause 2: The admin account isn't mail-enabled.
- Cause 3: After Exchange Server 2003 is uninstalled, the Servers container in the Administrative Group (the First Administrative Group or another custom administrative group in Exchange 2003) is empty.
Solution 1: Add the OU=EXTERNAL (FYDIBOHF25SPDLT) public folderAdd the OU=EXTERNAL (FYDIBOHF25SPDLT) public folder. To do this, follow these steps on the mail server:
- Connect to the server that contains the on-premises Exchange 2010 public folder.
- Open the Exchange Management Shell, and then run the following cmdlet:
- Install a new External Schedule+ Free Busy public folder. To do this, run the following cmdlet:
- Run the following cmdlet, and then make sure that all public folder servers have the External Schedule+ Free Busy public folder.
Get-PublicFolder "\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY" -recurse | fl identity
\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY\EX:/O=<OrganizationName>/OU=EXTERNAL (FYDIBOHF25SPDLT)
Solution 2: Mail-enable the Exchange admin accountNote You should always mail-enable Exchange admin accounts. If the Exchange admin account isn't mail-enabled, the Hybrid Configuration wizard may fail during the Set-HybridConfiguration or Update-HybridConfiguration process, and you may receive the following error message:
Solution 3: Use ADSI Edit to remove the empty Servers containerWarning This procedure requires ADSI Edit. Using ADSI Edit incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems that result from the incorrect use of ADSI Edit can be resolved. Use ADSI Edit at your own risk.
- Start ADSI Edit. To do this, click Start, click Run, type adsiedit.msc, and then click OK.
- Expand the Configuration container (<ServerName>.<DomainName.com>), and then expand CN=Configuration,DC=<DomainName>,DC=local.
- Expand CN=Services, expand CN=Microsoft Exchange, and then expand CN=<ExchangeOrganizationName>.
- Expand CN=Administrative Groups, and then expand CN=first administrative group (where first administrative group belongs to Exchange 2003).
- Expand CN=Servers, and then verify that there are no server objects listed in the Servers container.
- Right-click the empty CN=Servers container, and then click Delete.
- Intercept free/busy requests
- Send the requests to Office 365 for lookup
Still need help? Go to Microsoft Community or the Exchange TechNet Forums.
Article ID: 2816904 - Last Review: Dec 28, 2016 - Revision: 1