Microsoft 365 outage is over, and the email backlog is cleared

If an email you were waiting for on Friday never turned up, check again. Microsoft says its 365 outage is fixed and the backlog of mail that built up has been cleared.

Microsoft posted its final update on its public status page at about 11:50am Perth time on Saturday. It says services “have fully recovered and the backlog of email messages has been processed”. It puts the incident at 6:05pm Thursday to 12:10am Saturday, Perth time.

We covered the outage as it happened in Microsoft 365 outage drags into Friday afternoon: what still works. This is what’s changed, and what to tidy up before Monday.

Back on Friday night, Asia Pacific first

Recovery started at about 10pm Sydney time on Friday (7pm in Perth), iTnews reports. Microsoft first reported success on parts of its Asia Pacific infrastructure, then in other regions.

That order may have been influenced by Australia’s digital resilience agreement with Microsoft, iTnews suggests. Home Affairs Minister Tony Burke said the agreement was activated on Friday. He said it was activated “to make sure that we get appropriate prioritisation of Australian interests”. The agreement is a memorandum of understanding on protecting critical systems, signed with Microsoft.

Friday’s mail turned up late, and out of order

Messages held up during the outage have now been delivered. But iTnews found that scheduled emails sent during the day arrived hours out of order. It also reports that Microsoft stretched its email timeout to 48 hours to help protect delayed messages.

In practice, an email you sent on Friday may have reached its recipient on Friday night or Saturday, or be sitting among newer mail.

Calendars were hit too. Microsoft listed failures with scheduling, invites, viewing and meeting edits in Teams. A meeting set up on Friday may not have reached everyone.

That matters for anything with a deadline: quotes, invoices, bookings and replies to customers. Don’t assume the other person saw it on Friday.

Workarounds to undo

Microsoft’s status page listed more than a dozen affected services beyond Outlook. A few of its suggested workarounds are worth reversing now.

• Sensitivity labels. Microsoft suggested removing a sensitivity label to export some Power BI and Fabric reports, where your organisation’s policies allowed it. Anything unlabelled that way should get its label back.
• Power Apps sign-ins. Microsoft suggested that people already signed in to the Power Apps or Field Service mobile apps avoid signing out, clearing app data or reinstalling. Anyone who held off on those steps can go ahead now.

One more for whoever manages your devices: Microsoft says Intune enrolment, check-ins and compliance policies may have been intermittently affected.

Not an attack, but no full answer yet

Microsoft says “this was a technical issue not related to cyber or AI [or] agents”, iTnews reports. It traced the fault to “an issue during an earlier network capacity upgrade” that surfaced after a recent network change.

It has promised a full post-incident report with the root cause and what it will change. That report is the one to read before deciding whether your business needs a better plan B for email. Our guide to backing up Microsoft 365 and Google Workspace is a good place to start that conversation.

Checklist

• Chase anything time-critical you emailed on Friday. Quotes, invoices and booking confirmations may have arrived hours late, so confirm the recipient has them.
• Look for Friday’s mail among Saturday’s. Delayed messages arrived out of order, so sort or filter by sent date to find anything from Friday.
• Check meeting invites and changes made on Friday. Microsoft listed failures with Teams meeting invites and edits during the outage, so confirm they went through.
• Put sensitivity labels back. If anyone removed a label from a Power BI or Fabric report as a workaround, reapply it.
• Check devices still show as compliant in Intune. Microsoft says enrolment, check-ins and compliance policies may have been intermittently affected during the outage.
• Read Microsoft’s post-incident report when it’s out. It will set out the root cause and Microsoft’s fixes.