When users try to connect to Outlook Web App by using the on-premises URL in a hybrid deployment of on-premises Exchange Server and Exchange Online, they receive the following error message:
“The Outlook Web App address https://www.<DomainName>.com/owa is out of date.”
This issue occurs if the TargetOwaURL parameter for the organization relationship isn't set correctly.
This parameter may not be set correctly for hybrid configurations that were created manually (such as in Exchange 2010 Service Pack 1 and earlier versions). The Hybrid Configuration Wizard sets this parameter correctly.
Make sure that the TargetOwaURL parameter is set correctly. To check whether this parameter is set correctly, open the Exchange Management Shell on the on-premises Exchange server, and then run the following command:
The TargetOwaURL parameter specifies the Outlook Web App URL of the external organization that's defined in the organization relationship. This parameter is used for Outlook Web App redirection in an Exchange hybrid deployment scenario. When this parameter is set, users in the organization can use their current Outlook Web App URL to access Outlook Web App in the external organization.