EWS Migration
Microsoft Is Discontinuing Its Exchange Web Services (EWS) for Microsoft 365
Microsoft has announced that it will no longer support Exchange Web Services (EWS) for Exchange Online as of October 1, 2026. This decision affects all companies that use EWS in combination with Exchange Online (Microsoft 365).
EWS is a technology that was developed specifically for accessing Exchange data. The API enables access to data from Microsoft Exchange Server and Exchange Online, including emails and mailboxes. EWS has been a central interface for third-party solutions such as archiving systems.
What Will Happen in October? Microsoft plans to disable EWS for Exchange Online starting October 1. This decision will force manufacturers to switch to the Microsoft Graph API.
Please note: If you use Exchange Online Kiosk, Microsoft Office 365, and Office 365 F1/F3, you should make the change by June. Further information can be found here.
What Will Change for MailStore Server and the MailStore SPE?
The shutdown of EWS initiated by Microsoft will require adjustments to MailStore Server and the MailStore SPE, depending on your archiving strategy. This is because archiving methods within MailStore Server and MailStore SPE that were accessing EWS will no longer be available from October 1 and will then run into errors.
The following profiles are expected to be affected from October onwards, Graph API does not expose access to these and support is effectifely dropped:
- Importing Exchange Online archive mailboxes
- Importing Exchange Online public folders
Regular Exchange Online Mailboxes and Shared Mailboxes are available using Graph API. New mailbox archiving profiles in MailStore will use Graph API starting with version 26.1. New export profiles will change with version 26.2. Existing EWS archiving and export profiles will work Until October 2026. We will offer a migration path in the coming months.
The summary panel of the archiving or export profile tells which protocol is used. Microsoft 365 Journal archiving profiles do not typically use EWS and are therefore not affected.
