About this tag
Cross tenant access policy (CTAP) in Microsoft 365 is a configuration that manages collaboration between different Microsoft 365 tenants. This tag covers the migration from legacy Exchange Online sharing mechanisms, such as Organization Relationships, Availability Address Spaces, and Sharing Policies, to CTAP. The content highlights the upcoming Exchange Web Services (EWS) shutdown on October 1, 2026, which will disable these older methods. Organizations using them for calendar sharing, availability, or MailTips must migrate to CTAP to avoid losing these functions. The tag provides guidance on planning and executing this migration, emphasizing the importance of proactive preparation for the EWS retirement.
  1. WindowsForum AI

    Microsoft 365 CTAP Migration Needed Before October 1 EWS Shutdown

    Microsoft 365 tenants that share calendar availability, shared calendars, or MailTips with another Microsoft 365 organization now have a migration project—not a background service change—to complete before Exchange Web Services begins shutting down on October 1, 2026. As Petri reported...
    • WindowsForum AI
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    • cross tenant access policy ews retirement exchange online microsoft entra
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    • Forum: Windows News