Microsoft 365 outage: Outlook is recovering after about 18 hours. What happened and what to do

Updated Nov. 13, 2026, 6:50 a.m. MT: Microsoft 365 is recovering after roughly 18 hours of disruption. At 6:32 a.m. MT, Microsoft reported "continued recovery progress across affected regions," with broader improvements in North America. It also warned that some users may still see intermittent access problems or delayed mail. Microsoft says it has extended email timeouts to 48 hours to preserve delayed messages, and that there's "no evidence of malicious activity" (per TechCrunch). It still hasn't named a root cause. See what changed overnight and what to do as service comes back.

Earlier update, Nov. 12, 2026, 4:03 p.m. MT: Microsoft hadn't declared the outage over. Its 3:09 p.m. MT update said earlier fixes "have not provided the anticipated relief."

Overnight: what changed (Mountain Time)

From Microsoft's posts on @MSFT365Status, Nov. 12–13:

• 5:06 p.m.: Servers Microsoft returned to service "can become unresponsive again once they receive traffic." Microsoft starts limiting which types of traffic reach the affected infrastructure.
• 6:59 p.m.: Microsoft reports "positive results" from restarting affected infrastructure in an isolated way.
• 8:13 p.m.: Microsoft says changes applied to improve service are "not taking as expected" and looks for other ways to add capacity.
• 9:36 p.m.: Microsoft says it's redistributing traffic and applying "strategic traffic blocking measures," and it sees partial recovery where those are in place.
• 12:44 a.m.: Microsoft reports "positive results for service stability and increased capacity" from its latest traffic changes and starts rolling them out more broadly.
• 2:24 a.m.: "To help preserve delayed mail during this event, we've extended email timeout to 48 hours."
• 4:11 a.m.: Microsoft reports improvements in mailbox access and delayed email processing as traffic is gradually restored.
• 6:32 a.m.: Microsoft reports "broader improvements in North America, sustained improvements across much of Europe, and encouraging recovery signals in Asia Pacific."

TechCrunch reports the outage also hit Copilot, Defender and admins' Intune dashboards, and that Kentik's Doug Madory saw traffic returning after about 18 hours of downtime.

What to do as service comes back

1. Give delayed mail time. With the 48-hour timeout, mail sent to you during the outage should arrive late rather than bounce. Don't ask everyone to resend just yet.
2. Check your Outbox and Sent Items. Anything you wrote while offline may still be waiting, or may go out late. Resend only what didn't go.
3. Restart Outlook once. If the app still shows "Disconnected" after Microsoft reports recovery in your region, quit and reopen it. Don't remove and re-add your account.
4. Follow up on anything urgent. Microsoft says some users may still see intermittent problems. Confirm time-sensitive emails by phone or another channel.
5. Stay alert for scams. Fake "reactivate your mailbox" emails usually follow big outages. Get your updates from Microsoft's status page or its X account.

The skim (from Nov. 12)

• What's down: Microsoft 365 email. Since about 10:54 a.m. MT, people have been unable to reach Outlook and Exchange Online mailboxes on the web, desktop and phone. Microsoft says the problem may affect Microsoft 365 connectivity "in any region." It's tracking the outage as incident EX1550543.
• Why, so far: Microsoft says a number of servers became unexpectedly unavailable and failed automated health checks, which pushed load onto the rest of its servers. It hasn't named a root cause.
• What to do: nothing on your device will fix this. Don't reinstall Outlook or reset your password. Watch Microsoft's public status page, and be wary of anyone offering to "fix" your account.

What's affected

Microsoft first said users were having trouble "accessing Exchange Online mailboxes through multiple connection methods in the Americas." Thirteen minutes later it widened that to Microsoft 365 connectivity "for users in any region," according to the Microsoft 365 Status account on X.

• Outlook everywhere: the incident covers Outlook on the web, MAPI (the connection the Outlook desktop app uses), Exchange ActiveSync (used by many phone mail apps) and REST API access, per Microsoft's incident details as reported by How-To Geek.
• Other Microsoft 365 apps: TechCrunch reports that Microsoft also listed Teams, SharePoint, Copilot and Defender XDR as affected. It says consumers lost access to OneDrive and Office for the web too. Microsoft's own status page says only that users "may be unable to connect to multiple Microsoft 365 services."
• Business and personal accounts: TechCrunch says the outage hit both business and consumer users.
• AI tools: OpenAI and Anthropic said the Microsoft 365 connectors in ChatGPT and Claude were affected, The Guardian reports.

The outage tracker Downdetector logged nearly 130,000 reports of Outlook problems just after 11 a.m. MT, AP reports. The BBC cites more than 131,000 US reports at 11:15 a.m. MT. Downdetector counts user reports, not confirmed affected accounts, and reports have since fallen from that peak.

A separate, earlier Teams problem in North America (incident TM1550488) started around 8:40 a.m. MT. Microsoft said it was "fully resolved" at 10:09 a.m. MT.

Timeline (Mountain Time)

All times are from Microsoft's posts on @MSFT365Status unless noted.

• 10:54 a.m.: Microsoft starts investigating mailbox access problems in the Americas under EX1550543.
• About 11 a.m.: Downdetector reports spike (AP, BBC).
• 11:07 a.m.: Microsoft says the issue may affect users "in any region."
• 11:35 a.m.: Microsoft says part of its infrastructure is under "elevated load across multiple regions" and adds a second ID, MO1550821. It hasn't said what MO1550821 covers.
• 11:48 a.m.: Microsoft begins redistributing connection traffic across its worldwide infrastructure.
• 12:12 p.m.: Microsoft says it has paused all deployments and is moving traffic off the affected servers and restarting them.
• 12:31 p.m.: The load "isn't driven by an increase in traffic," Microsoft says, but by servers being "unexpectedly unavailable."
• 12:50 p.m.: Microsoft is testing a configuration change for servers failing automated health checks and restarting all affected servers.
• 1:19 p.m.: Microsoft says it hasn't found a recent change that lines up with the start of the outage. The failed health checks "may originate from a specific component" that processes server health.
• 2:00 p.m.: A different health check method lets "a subset of affected servers" come back, and Microsoft starts applying it more broadly. It's the first sign of partial recovery.
• 2:40 p.m.: Microsoft is still restarting servers. It's also "assessing whether reverting a small number of recent configuration updates" could speed up recovery.
• 3:09 p.m.: Microsoft says its actions "have not provided the anticipated relief." It found "a core process on affected servers is becoming overwhelmed." It's isolating part of its infrastructure, restarting components and slowly bringing traffic back to test a possible recovery before rolling it out more widely.
• 4:03 p.m.: No newer Microsoft post. The status page still says "Service degradation" for Microsoft 365 (Business or Enterprise).

What Microsoft has said about the cause

Microsoft has described what's happening but not what started it. Servers are failing health checks, getting pulled out of service, and the remaining servers can't handle the load. Microsoft has given two possible culprits: a component that processes health checks, and a core process that gets overwhelmed. Each time, it called its findings an investigation, not a conclusion.

Microsoft has mentioned "recent configuration updates" only as something it might roll back to speed up recovery. It hasn't said they caused the outage. It also hasn't given an estimated time for a fix.

TechCrunch notes this follows a days-long Microsoft 365 outage in September, which Microsoft blamed on a "core authentication configuration" issue.

What you can do right now

1. Check the status, not your settings. The problem is on Microsoft's servers. Reinstalling Outlook, removing your account, resetting your password or restarting your router won't bring email back. Removing and re-adding an account can also mean a long re-sync once service returns.
2. Use the public status page. Microsoft points people to status.cloud.microsoft and @MSFT365Status when the admin center won't load. IT admins can look up EX1550543 and MO1550821 under Health > Service health in the Microsoft 365 admin center, if it opens for them.
3. Read what you already have. If the Outlook desktop app keeps a local copy of your mailbox, mail that downloaded before the outage may still open offline. Messages you write may sit in the Outbox until Outlook reconnects.
4. Double-check important sends later. Once service is back, look in Sent Items and the Outbox for anything time-sensitive. Microsoft hasn't said whether incoming mail is delayed or lost during the outage, so follow up on anything urgent by phone or another channel.
5. Watch for outage scams. Microsoft hasn't called this a security incident. Even so, outages are a good cover for fake "verify your account" emails, texts and calls. Microsoft is posting its updates on its status page and X account, so don't sign in through a link someone sends you.

This isn't the Outlook zero-day

Today's outage is a different problem from yesterday's Outlook zero-day, CVE-2026-124194. That one is a security flaw in Outlook for Windows that attackers are exploiting to leak sign-in hashes. It's fixed by updating Office, not Windows. This outage is an availability problem on Microsoft's servers, and Microsoft hasn't linked the two. If you haven't installed that Office update yet, do it once Microsoft 365 is working again.

Skimwire couldn't independently measure the outage's scope. This report from our AI-assisted Apps desk is based on Microsoft's public status posts and the reporting linked below, and we'll update it as Microsoft posts new information.

Sources: Microsoft 365 Status, 6:32 a.m. MT Nov. 13 and overnight posts (checked 6:45 a.m. MT, Nov. 13, 2026); TechCrunch, Nov. 13; Microsoft 365 Status on X (posts from 8:40 a.m. to 3:09 p.m. MT, checked 4:03 p.m. MT, Nov. 12, 2026); Microsoft Service Health Status (checked Nov. 12, 2026); TechCrunch; The Verge; AP; BBC; The Guardian; How-To Geek.