Article ID: 2816904 - View products that this article applies to.
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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.
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