BOBcloud Microsoft 365 backup already runs on the Microsoft Graph API. The migration was completed in our current platform release, so Exchange Online mailbox backup does not use EWS.
One thing to be aware of: public folders and archive mailboxes have no Graph equivalent at all. That is a limitation of the Microsoft platform and affects every backup product, not just ours — see below.
Summary
Microsoft is retiring Exchange Web Services (EWS) in Exchange Online. From 1 October 2026 tenants that have not explicitly enabled EWS are switched to blocked, on a rollout that reaches tenants at different times. EWS is permanently shut down on 1 April 2027.
New Microsoft 365 backup sets need no action. Sets created on the current build authorise against Microsoft Graph from the outset.
Existing backup sets may need their Microsoft 365 authorisation refreshed so the new Graph permissions are granted. See below.
An industry-wide change, not a BOBcloud one
This is a Microsoft platform change affecting every product that reads Exchange Online data. Backup vendors, CRMs, phone system integrations, archiving tools, migration utilities, signature management and meeting room booking systems have all been working through the same transition.
It is worth knowing simply because backup is rarely the only thing in a tenant using EWS, and the others are easy to overlook. Most vendors have a plan; the question is usually what each one needs you to do, and by when.
What is and is not affected
| Data type | Affected? |
|---|---|
| Email, calendar and contacts | Not affected — we back these up over Graph |
| OneDrive | Not affected — has never used EWS |
| SharePoint | Not affected — has never used EWS |
| Teams files | Not affected — stored in SharePoint |
| Public folders | Affected, and permanently — see below |
| Archive mailboxes | Affected — no Graph equivalent exists |
| Teams chat | Worth checking — chat history lives in a hidden Exchange folder |
Timeline
What this means for your accounts
We have been pushing out the required update to all accounts that need it.
If you see any backup errors on a Microsoft 365 set, you will need to re-authenticate the Microsoft 365 connection in the BOBcloud desktop software. Edit the backup source on that set — this spawns a new authorisation request with Microsoft 365. Sign in and approve it, and the set is back on Graph. It takes a couple of minutes per account.
If the automatic update does not arrive
Most devices will update themselves and need nothing from you. Occasionally a firewall blocks the update, in which case that device needs updating manually. The current client is available from the portal:
- portal.bobcloud.net — current portal
- portal.data-stor.net — legacy portal
Sign in, download the client, and run the installer on the affected device. If you are not sure which portal applies to your account, ask us and we will check.
What Graph does not cover
These are gaps in the Microsoft Graph platform itself. They affect every backup product equally rather than any one in particular, and there is nothing a vendor can do about them until Microsoft closes them.
Public folders
Microsoft has stated in its retirement announcement that it will not provide APIs for programmatically creating, reading, updating or deleting public folders after October 2026. This is a decision rather than a temporary gap.
In practice that means public folder data in Exchange Online will not be reachable by any third-party tool — backup, archiving, migration or sync — once EWS is blocked in that tenant. Microsoft's own recommendation is to migrate public folder content to Microsoft 365 Groups, which are fully supported by Graph.
If any of your customers still use public folders, those backups will fail once EWS is blocked in that tenant. There is no workaround at the backup layer.
Archive mailboxes
Microsoft has not released a Graph API for in-place archive mailbox access. If a customer depends on archive mailbox backup, check what your retention and compliance position is without it.
Microsoft 365 Group mailboxes
Also not currently supported by Graph. Microsoft lists import and export for Groups and public folders as work still in progress.
Other gaps
Microsoft has also named folder associated information, and has said the published list is not exhaustive — some functionality may not reach Graph at all.