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Microsoft 365 migration guide

Prepare your app for Exchange Online EWS retirement

Microsoft is rolling out EWS retirement in Exchange Online. Confirm Microsoft's current tenant guidance and inventory the applications that still use EWS.

Dates last checked September 30, 2026. Microsoft Exchange announcement ↗

October 1, 2026Start of Microsoft's phased disablement. Under the announced policy, tenants without the specified allow list and admin setting are blocked by default; rollout and controls vary by tenant.
April 1, 2027Microsoft's announced date for permanently disabling EWS in Exchange Online.

  1. Find the applications and tenants involved

    Ask application owners and review the Microsoft 365 EWS usage report. A quiet week may miss quarterly or seasonal workloads; use an appropriate reporting window.

  2. Separate Exchange Online from on-premises Exchange

    The retirement concerns Exchange Online. On-premises Exchange continues to use EWS; hybrid applications may have both paths.

  3. Check each call path and limitation

    Run the private usage check and compare the results with the coverage matrix. Action names do not reveal every request option or folder type.

  4. Test the identity and workload

    Verify Graph permissions, mailbox scope, stored IDs, sync behavior, search, paging and notification handling in a non-production environment.

  5. Follow Microsoft's tenant-specific instructions

    Microsoft describes the rollout, exclusions and controls in its announcement. Confirm how the announced policy applies to each tenant before setting your own change date.

We will support every EWS operation with a production-supported Graph equivalent and add each one to the matrix after testing. The only external wait is for Microsoft to provide an API where one does not exist yet. Current gaps are listed in the matrix.
Check EWS usageRead migration steps