No support for MS Exchange Web Services from October 2026?

[Maurice Smeets]

Hello, I received a message from Microsoft about Exchange Web Services being deprecated in favour of MS Graph from Oct. 2026. Obviously, Calengoo uses EWS in Exchange Online to enable Exhange accounts in the Calengoo application.

Will you upgrade to MS Graph before the mentioned date? Otherwise we will loose the Exchange support in Calengoo from Oct. 2026.

Below the content of the message from Microsoft:

In 2018, we announced that we were no longer making feature updates to Exchange Web Services (EWS) in Exchange Online, and we advised developers to move to Microsoft Graph.

In September 2023, we announced that on October 1, 2026, we will start blocking EWS requests to Exchange Online.

We are now less than 12 months from October 1, 2026. We have made progress on closing several parity gaps with more changes in development to be released in the coming quarters. Please refer to Deprecation of Exchange Web Services in Exchange Online for up-to-date guidance and roadmap information.

You are receiving this notification because there are EWS applications in your tenant.

If you haven't already, start the process of working with your application development organization and your application vendors to either sunset or migrate active EWS applications on your tenant to the Graph API or Power Platform, or Copilot Declarative Agents.

While we are aware of certain parity gaps in Graph API we can confidently say based on EWS usage telemetry that the vast majority of custom LOB EWS applications can already be safely migrated to alternative technologies.

When this will happen:

October 1, 2026

How this affects your organization:

In October 2026 we will begin disabling EWS on all M365 tenants worldwide. EWS Applications that have not been migrated will stop functioning.

The following applications on your tenant use EWS:

Entra Application ID

420d53be-***********************

Next Steps

1. Review your application portfolioG(1.1TM1.2 now to get an understanding of which apps need to be updated by your organization and which applications require updates from vendors.to get an understanding of which apps need to be updated by your organization and which applications require updates from vendors.

2. Prioritize EWS app modernization on your engineering schedule to ensure enough time to address any functionality gaps

3. Disable EWS in your tenant when you no longer have applications that depend on it.

We know there are certain parity gaps in Graph API but based on EWS usage telemetry we know that the vast majority of EWS applications can already be safely migrated to Graph API.

We encourage you to take the next step and begin the modernization process. Refer to Deprecation of Exchange Web Services in Exchange Online for up-to-date guidance and roadmap information.

We also provide a set of open-source tools and tutorials to aid in discovery, analysis and AI assisted modernization of EWS applications.

We will publish regular communications as we progress towards this deadline to aid affected tenants in identifying EWS usage. We encourage all customers to monitor Message Center and the Exchange Blog and Deprecation of Exchange Web Services in Exchange Online for related content.

Thank you in advance for updating and opening your apps to a wider range of useful and intelligent features on Microsoft Graph. We are extremely excited about the growing opportunities that Microsoft Graph offers to developers, and we remain fully committed to our journey to empower developers to access Microsoft 365 data with the most modern features and tools.

[CalenGoo Support]

Hi,

there is already Microsoft Graph support, e.g. under "Settings > Accounts > Add account > Microsoft Office 365 (Graph API)".

Is that what you were looking for? Or is it missing somewhere?

Kind regards

Dominique Gunia