Thursday afternoon was a sharp reminder of how much of the working day runs through one Microsoft service. Exchange Online started failing just after four o'clock UK time, and as I write on Friday, Microsoft 365 still hasn't fully recovered. Teams calls mostly carried on, but nearly everything around them, from calendars to Copilot, went down with the mailbox.
That dependency runs through the rest of the week's news too. In this week's roundup I look at what the outage exposed, my interview with Pexip's Jordan Owens, Anthropic's Claude Meetings and two device deadlines, plus my take on whether your meetings would survive a day without Exchange. I've also picked out news from Telia, Microsoft and Google.
Editor's Pick: Microsoft 365 Outage Shows How Much Runs Through Exchange
Microsoft opened Exchange Online incident EX1550543 at 16:17 GMT on Thursday, November 12, after users couldn't reach their mailboxes. A second incident for the rest of Microsoft 365 followed two hours later, and by Friday morning the outage had run for more than 15 hours with no recovery time given, as Rob Scott reported for UC Today.
The outage hit Teams unevenly. Calls, meetings, group chats and standard channels largely kept working, Microsoft said. The trouble was with everything that leans on Exchange, including calendars, invites, meeting edits and Live and Virtual events. Copilot chat either failed to load or couldn't see email, calendar and files. Even Anthropic said its own Microsoft 365 connector was failing for most requests.
Microsoft hasn't yet given a root cause, but Charles Lamanna, Executive Vice President at Microsoft, ruled out an attack overnight:
There is no indication this is the result of malicious or cyber activity.
Early fixes didn't hold. At the time of writing, Microsoft's service health page says traffic "is being gradually restored," but "some users may continue to experience intermittent issues."
For buyers, the bigger lesson is about how the suite is built. In November 2024, an Exchange change took down Teams calendars and Outlook for a Monday morning. This one lasted through the night and reached much further, because far more of Microsoft 365 now routes through Exchange, Copilot included. Rob put it well:
If your email, calendar and Copilot all sit on the same Exchange dependency, you don't have a backup. You have a single point of failure with a familiar interface.
When Microsoft's promised post-incident report arrives, read it alongside your own incident log.
Pexip's Jordan Owens Says Meeting Interop Is Now About Data
Jordan Owens, CTO for the Americas at Pexip, told me in this week's interview that the next phase of meeting interop is about data. Native join between Teams, Zoom and Google Meet is now standard, and Owens says that's enough for an organization that lives on one platform. The difficulty starts when you join another vendor's meeting and your own tools stay behind:
Meeting interop is no longer about meeting interop. It's about data interop between meetings.
He wants the host to stop deciding which AI and data each participant can bring:
If I'm a Zoom shop, I should be able to use Zoom AI Companion when I dial into a Teams meeting and get the value out of that.
That will take real work on permissions and data residency across rival platforms. For buyers, the bar has moved. Getting into the meeting is now the easy part, and the harder job is keeping your own context and controls once you're there. Watch the full interview for where he thinks native interop runs out.
Anthropic Puts Claude Inside the Meeting, Starting With Google Meet
Anthropic took its own route into the meeting on November 12, when it launched Claude Meetings in beta. Claude joins the call as a visible participant, taking notes and building docs and whiteboards while people talk. For now it joins Google Meet only, with other platforms "coming soon," and it's rolling out on Team and Enterprise plans.
Check the defaults first. On Team plans it's on unless someone turns it off, while Enterprise admins have to switch it on. Sophie Wilson argued this week that faster notes won't help much if nobody owns the decision, and in his take on the launch, Rob asks whether the follow-up work will ever find its way back into Teams and PowerPoint. Either way, it's one more AI tool to map against the calendar it depends on.
Teams Admin Center and Neat Set Device Deadlines Before Christmas
Microsoft is moving management of Android rooms, panels, phones and SIP devices from the Teams Admin Center to the Teams Rooms Pro Management portal. In public clouds, SIP devices, Android rooms and panels start losing TAC administration by mid-November, finishing by the end of the month, according to Microsoft's transition guide. Phones follow from early December and finish by December 15.
The timetable has already slipped once since we reported on October 2 that it would end in September. Check now that you hold a license that opens the portal, such as Teams Rooms Pro, Basic or Standard, or Teams Shared Space.
Neat owners have a deadline of their own. The company is rolling out Neat OS 26.6.3 to fix CVE-2026-111497, a flaw in the Brotli decoder that CISA lists as exploited. The staged rollout began on November 7 and is due to finish by November 21, Neat says in its advisory. Neat says it has no evidence of attacks on its devices, but rooms with automatic updates turned off won't patch themselves, and those are the ones to chase.
Talking Point: Would Your Meetings Survive a Day Without Exchange?
What interests me most about Thursday is that it was only a partial failure. Teams meetings mostly worked, but finding, scheduling and changing them often didn't, and the AI tools many organizations rolled out this year lost the inbox and calendar they rely on.
Nobody should walk away from Microsoft over one bad day. Most continuity plans, though, treat the meeting platform as either up or down, and this week showed a messier middle ground, where the call works and the things around it don't.
If I were running IT, I'd use the week before Ignite to write down how staff would join critical meetings without a calendar, and what replaces email when an urgent notice has to go out. I'd also decide which Copilot workflows should simply pause when Exchange goes dark.
Poll: If Exchange Online went down for a full working day, could your organization still run its critical meetings?
- Yes, we have a tested fallback for scheduling and joining
- Mostly, but we'd rely on people improvising
- Only for internal calls, not external ones
- No, our meetings depend on the calendar
In Other News: Telia, Teams Free and Google Chat
A few other UC&C stories I picked out from this week's In Brief feed.
- Telia pays SEK 3.8 billion for Telavox's Nordic enterprise base. Telia says it will take on about 24,000 mostly small and midsize customers and license Telavox's UCaaS platform, with the deal expected to close in Q1 2027 (In Brief).
- Teams is retiring off-network invitations to Teams Free. From December, users won't be able to invite outsiders to create a Teams Free account by email or chat link, Microsoft told admins (In Brief). Meetings aren't affected, but helpdesk guidance should be updated before December 6.
- Gemini can now book meetings from Google Chat in one click. Google said the feature is on by default wherever smart features are enabled, with no dedicated admin switch (In Brief), so admins who want a say should check those settings.
Looking Ahead to Microsoft Ignite 2026
Next week is Microsoft Ignite, from November 17 to 20 in San Francisco, with Satya Nadella keynoting on Tuesday. In my Ignite preview I said the big question was whether Microsoft would put numbers on Copilot's value. After this week, I'll be listening just as closely for what it says about resilience. If the outage has changed how you plan for Microsoft 365, or you'd like to compare notes at Ignite, get in touch.
