Check which Microsoft 365 services are affected
An incident can affect email, file access or authentication differently. Ask an administrator to check your organisation’s service-health information, and use Microsoft’s public status page when the admin service is unavailable. The Microsoft service-health documentation explains where to find tenant-specific information.
List the work that has stopped: receiving orders, answering customer questions, preparing quotations or opening shared files. This business view is the starting point for deciding what needs a separate continuation route.
Outlook and Exchange Online during an outage
Previously downloaded email may remain accessible in a prepared desktop client. That does not make new messages arrive, restore a cloud sign-in service or give every colleague the same local view.
Our Outlook outage guide explains the difference between Outlook.com, the Outlook application and business Exchange Online accounts. For a shared local capability, the design must agree mailbox scope, local authentication, routing and what happens when Microsoft’s service returns.
OneDrive and SharePoint offline access
A file name in File Explorer does not prove that its contents are stored on the device. With OneDrive Files On-Demand, some items are placeholders that need the cloud before they can open. Microsoft describes the difference in its Files On-Demand guidance.
For selected documents, the option labelled Always keep on this device can prepare local availability while the service is reachable. Confirm the download has finished and test opening the file without cloud access. Changing that setting after the source becomes unavailable cannot fetch missing content.
For a team-wide environment, agree which OneDrive folders and SharePoint document libraries are copied to the on-site file workspace. Permissions, file formats, editing and reconciliation all need testing. A local copy of a document library does not recreate SharePoint’s full application behaviour.
Include identity and cloud-only applications in the plan
Local data is useful only if staff can authenticate and open it. Check whether signing in, obtaining a key, launching an application or finding the procedure still depends on Microsoft’s affected services.
Teams meetings, cloud workflows, Power Platform applications and other SaaS features need their own decisions. Do not assume a local mailbox and file server reproduce the whole Microsoft 365 suite. Define the essential tasks that can run locally and identify a separate approach for everything else.
What an on-site Microsoft 365 continuity environment adds
An on-site continuity appliance brings agreed mailbox and file content into a prepared local service layer. The important difference is a tested place to work with that content, rather than simply a restore point held elsewhere.
Synchronisation runs continuously with service-specific timing; provider APIs, permissions and connectivity affect the gap. Separate snapshots or independent backups are still needed for unwanted changes and deletion. Read backup versus continuity before choosing the design.
After an interruption, record what was inaccessible, how long the business could tolerate it and who needs local access. Talk to Orwell about Microsoft 365 continuity with those requirements, or start with our planning checklist.