When a Microsoft 365 outage occurs, your Google Workspace environment is already prepared with a synchronised copy of your users' mail data. This article explains what to do as an administrator and how to guide your end users through the failover.
How you will know M365 is down
You may become aware of an M365 outage through any of the following:
- User reports of being unable to access Outlook or other M365 services
- Microsoft's own service health dashboard or status page
- Third-party outage monitoring services
Steps for administrators
When you confirm an M365 outage, follow these steps:
1. Check your sync status
Open the CloudM Continuity dashboard and review:
- Last successful sync — When was the most recent sync completed? This tells you how current the Google Workspace data is.
- Failed Users — Were any syncs already failing before the outage began? The Failed Users card gives you the count at a glance.
- Per-user detail — Use the Sync Status page to spot any users with stale or failed syncs.
This gives you a clear picture of the data state your users will be working with in Google Workspace.
2. Notify your users
Send your pre-prepared notification directing users to switch to Google Workspace. Your notification should include:
- Confirmation that M365 is currently unavailable
- Instructions to access email at
mail.google.com - A reminder that their Google Workspace mailbox contains their synced M365 mail
- Reassurance that any mail they send or receive in Google Workspace during the outage is kept safe there, and can be synced back to Microsoft 365 by an administrator once the outage is over
Send notifications via a channel that does not depend on M365
If your organisation uses Microsoft Teams or Outlook for internal communication, those channels will also be affected by the outage. Use an alternative channel such as Google Chat, Slack, SMS, or your company intranet.
3. Monitor the situation
During the outage:
- Keep an eye on the CloudM Continuity dashboard and Sync Status page
- Check the audit logs for any errors or warnings
- Note the time the outage began — this will be useful when reviewing the recovery later
- Follow Microsoft's status page so you know when the service is restored
What your end users experience
From your end users' perspective, the failover is straightforward:
| What users can do | Detail |
|---|---|
| Read existing email | All mail synced up to the last completed sync is available in their Google Workspace mailbox, including folder structure |
| Send new email | Users can send email from their Google Workspace account during the outage |
| Receive new email | Routing incoming email to Google Workspace during an outage is managed by you (or your partner) through your own DNS/MX configuration — CloudM Continuity does not manage mail routing. Plan and test your routing approach as part of failover readiness. |
Data gap
Users should be aware that emails received between the last completed sync and the start of the outage may not yet be in Google Workspace. The size of this gap depends on your sync frequency tier — up to 1 hour for Premium, up to 24 hours for Standard, or up to 7 days for Basic.
When M365 comes back online
Once Microsoft confirms the service is restored and stable, you can bring the mail your users created in Google Workspace back to Microsoft 365 with a Recovery Sync. Recovery does not run automatically; an administrator starts it from the Recovery page.
- Confirm on Microsoft's status page that the service is fully restored. Recovery writes data into Microsoft 365, so starting while the service is still unstable can cause failures.
- Start a recovery from the Recovery page. Recovery Sync currently recovers mail, and recovered messages land in the correct folders in Microsoft 365.
- Follow progress on the Recovery page. You will see items synced counts, updated every few minutes.
- When the recovery finishes, review the summary. If it failed or completed with warnings, you can retry it; a retry re-runs all users in the recovery, and nothing is duplicated in Microsoft 365. Every completed recovery must be finished (moving it to the historic recoveries list) before a new one can start.
- Notify your users that they can return to using Microsoft 365.
For how recovery works in detail, see Understanding Recovery Sync.