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Microsoft Announces Phased Retirement of Exchange Web Services (EWS) in Exchange Online

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1 unique sources, 1 articles

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Microsoft plans to retire Exchange Web Services (EWS) for Exchange Online by April 2027, beginning with a phased disablement starting October 2026. EWS, a cross-platform API for accessing Exchange mailbox items, will no longer be supported in Exchange Online but will remain functional in on-premises Exchange Server installations. Administrators can manage the transition via an application allowlist, and Microsoft will conduct 'scream tests' to identify hidden dependencies. Developers are advised to migrate to the Microsoft Graph API, which offers near-complete feature parity with EWS.

Timeline

  1. 05.02.2026 20:07 1 articles · 4h ago

    Microsoft Announces Phased Retirement of Exchange Web Services (EWS) in Exchange Online

    Microsoft plans to retire Exchange Web Services (EWS) for Exchange Online by April 2027, beginning with a phased disablement starting October 2026. EWS, a cross-platform API for accessing Exchange mailbox items, will no longer be supported in Exchange Online but will remain functional in on-premises Exchange Server installations. Administrators can manage the transition via an application allowlist, and Microsoft will conduct 'scream tests' to identify hidden dependencies. Developers are advised to migrate to the Microsoft Graph API, which offers near-complete feature parity with EWS.

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Information Snippets

  • Microsoft will begin blocking Exchange Online EWS by default on October 1, 2026.

    First reported: 05.02.2026 20:07
    1 source, 1 article
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  • Administrators can temporarily maintain access via an application allowlist until April 1, 2027.

    First reported: 05.02.2026 20:07
    1 source, 1 article
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  • Microsoft will pre-populate allow lists for organizations that have not created their own by September 2026.

    First reported: 05.02.2026 20:07
    1 source, 1 article
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  • EWS will continue to function in on-premises Exchange Server installations.

    First reported: 05.02.2026 20:07
    1 source, 1 article
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  • Microsoft advises developers to switch to the Microsoft Graph API, which has near-complete feature parity with EWS.

    First reported: 05.02.2026 20:07
    1 source, 1 article
    Show sources

  • Only Exchange Server 2019 (Exchange SE) will support Graph for calls to Exchange Online, requiring hybrid customers to use Exchange SE to host on-premises mailboxes.

    First reported: 05.02.2026 20:07
    1 source, 1 article
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