Microsoft announced that the Exchange Web Services (EWS) API for Exchange Online and Office 365 will be retired in approximately three years. EWS is a cross-platform API that allows developers to create apps capable of accessing email messages, meetings, and contacts. These resources can be retrieved from various sources, including Exchange Online, Exchange Online as part of Office 365, and on-premises editions of Exchange.
The Exchange Team stated, “Today, we are announcing that on October 1, 2026, we will start blocking EWS requests from non-Microsoft apps to Exchange Online.” They assured users that while the EWS components will continue to receive security updates and certain non-security updates, there will be no changes to the product’s design or features.
This retirement only applies to Microsoft 365 and Exchange Online, with no impact on Outlook for Windows or Mac, Teams, or other Microsoft products. It’s worth noting that the retirement of EWS also applies to the EWS SDKs for Java and . NET. Microsoft advises developers to switch to the Microsoft Graph API, which will provide access to Exchange Online data.
However, the company acknowledged some feature gaps between EWS and Microsoft Graph, including no access to archive mailboxes, lack of folder-associated information and user configuration, and no Exchange Online management capabilities for third-party apps.
The Exchange Team is actively working on closing these gaps, but developers may need to find alternatives for features that won’t be included in the Graph API. Despite the inconvenience this may cause, Microsoft believes that retiring EWS will ensure more secure, reliable, and performant experiences.
They will publish regular communications to aid affected tenants in identifying EWS usage and encourage the adoption of Microsoft Graph for a wider range of useful and intelligent features.
In conclusion, developers using the EWS API are advised to begin transitioning to the Microsoft Graph API ahead of the retirement deadline. While some feature gaps exist, the tech giant says it is committed to addressing them and providing a seamless experience for users.