Retirement of Exchange Web Services in Exchange Online

[AdhocAdam]

Microsoft has announced that on October 1st, 2026, EWS requests from non-Microsoft apps will be blocked to Exchange Online.

As a result, this request seeks to enable the connector to handle connecting to hosted Exchange environments by introducing support for MS Graph as a means to read the contents of the inbox (i.e. the emails used for processing), instead of using Exchange Web Services to do so. #171 includes many (but not all) of the steps that would need to be factored into the current connector.

As a result of the proposed changes, a unique benefit to Exchange Online users would exist wherein the connector would no longer have a dependency on the EWS dll.

High level steps include:

• Further abstraction of the initial call to Exchange when retrieving messages:
  • Exchange on premise deployments via EWS
  • Exchange Online via EWS or MS Graph. This is probably a radio button that exists if you're using Exchange Online, thereby allowing you to define how you are connecting to Exchange Online. This would provide flexibility up until October 1st, 2026 so should an issue arise, a known working fallback exists.
• Replicating the message data points retrieved via EWS in MS Graph to ensure the connector continues to work as it does today for Exchange Online users
• Updating relevant documentation on configuring the Azure App associated with the connector
  • API Permission changes: Instead of using EWS.AccessAsUser.All the configured app would use MS Graph Mail.ReadWrite and Mail.Send
  • Verify reconsent/consent flow for current deployments