Microsoft 365 for Exchange Web Services (EWS) Service Ending
Microsoft is discontinuing the Exchange Web Services (EWS) for Microsoft 365. What does this mean for MailStore customers?
Microsoft Announces Discontinuation of Exchange Web Services (EWS) for Exchange Online
Microsoft has announced that it will no longer support Exchange Web Services (EWS) for Exchange Online as of October 1, 2026. This decision will affect all companies using EWS with Exchange Online (Microsoft 365), and thus many third-party solutions. The good news is, you should be well-prepared for a transition with MailStore.
What Are Exchange Web Services and Why Are They Needed?
EWS is an older technology designed specifically for accessing Exchange data. The API provides access to data from Microsoft Exchange Server and Exchange Online, including emails and mailboxes. For third-party solutions such as archiving systems, EWS has been a central interface until now.
What Happens in October?
Microsoft plans to shut down EWS for Exchange Online starting from October 1st. This decision forces producers to transition to the Microsoft Graph API. Microsoft Graph is a modern interface for the entire Microsoft 365 world, ranging from Outlook to Teams and OneDrive. This API provides access to resources and services within Microsoft 365 and serves as a central interface for integrations.
What Changes for MailStore Server and MailStore SPE?
The discontinuation of EWS initiated by Microsoft will require a configuration change in MailStore Server and MailStore SPE, depending on the settings of your archiving solution.
The reason for this is that archiving methods previously controlled via EWS in MailStore Server and MailStore SPE will no longer be available from October 1st and may encounter errors at that time. This applies to the following MailStore customers. Customers using MailStore Cloud are not affected by the EWS shutdown.
The following settings are expected to be affected in detail from October:
- Import of Exchange Online mailboxes
- Import of Exchange Online archive emails
- Import of Exchange Online public folders
- Exporting emails to Microsoft 365 (bulk export)
Next Steps for a Secure Transition
To be as well-prepared as possible, consider the following recommendations:
- If you have a folder, replace public folders with group mailboxes in a timely manner (see information from Microsoft). We will provide updates on this, and there is no need for immediate action. Follow our blog.
- We are here to help: Instructions and tools to ease the transition from EWS-based archiving profiles will be provided in due course. Until then, you are not required to take any action.
- Ideally, plan to move your Exchange Online archive mailboxes to MailStore before October for a smooth process.
- Please note: If you are using Exchange Online Kiosk, Microsoft Office 365, or Office 365 F1/F3, you should transition by June. Find more information here.
- We will continue to inform you: We will continue to share announcements to make the transition as easy as possible. Feel free to follow our blog, release announcements, and of course, the change log.
And remember: Keep your MailStore version up to date. Regular updates allow you to take advantage of new features and ensure that the software is always up to date.
The initial configurations will be done in the 26.1 version, which is expected to be released in mid-January. As always, we will inform you of all changes in our change logs.