Will the deprecation of EWS API support, prevent integration of on-premises Exchange accounts with non-Microsoft applications, making Microsoft Graph API the only supported method?

Question

As Microsoft is deprecating EWS API support starting October 1, 2026, I would like confirmation on whether this change will also affect the integration of on-premises Exchange accounts with non-Microsoft applications. After this change, will integrating on-premises Exchange accounts require the use of the Graph API exclusively, and will support for integrating on-premises Exchange accounts via the EWS API no longer be possible?

Answer 1

Hello Abhay Pundeer,

Thank you for contacting Microsoft!

For the query related to EWS API support, below provided information might be helpful.

The deprecation of the Exchange Web Services (EWS) API starting October 1,2026, will not affect the integration of on-premises Exchange Accounts with non-Microsoft applications.

After this change, integrating on-premises Exchange accounts will still be possible using the EWS API. However, for Exchange online mailboxes, you will need to use the Microsoft Graph API exclusively.

Please find the referenced link attached below for further information.

Link: https://techcommunity.microsoft.com/blog/exchange/retirement-of-exchange-web-services-in-exchange-online/3924440

Hope this helps.

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