Article ID: 2816904 - View products that this article applies to.
Not sure what release of Office 365 you're using? Go to the following Microsoft website:
Am I using Office 365 after the service upgrade?
When you try to run the Hybrid Configuration Wizard to enable a hybrid configuration in Microsoft Office 365, you receive the following error message:
Hybrid Configuration Failed with error "execution failed: Configure Legacy Exchange Support"
This issue occurs if there's a failure to install the "External Schedule+ Free Busy" public folder for Microsoft Exchange Server 2003 Support in a hybrid deployment. In this case, the "OU=EXTERNAL (FYDIBOHF25SPDLT)" public folder is missing from the public folder hierarchy.
To resolve this issue, add the OU=EXTERNAL (FYDIBOHF25SPDLT) public folder. To do this, follow these steps:
The External Schedule+ Free Busy folder is used in hybrid scenarios when Exchange Server 2003 or Microsoft Outlook 2003 is used on-premises. This external folder is installed on the Exchange 2010 public folder server so that the server can do the following:
This process is performed only for the accounts that are migrated from on-premises to the cloud. Exchange Server 2003 users still have calendaring functionality.
Still need help? Go to the Office 365 Community
Contact us for more help
Connect with Answer Desk for expert help.