When Will Outlook Be Back Up? Outage Timeline and Status

When will Outlook be back up?

Short answer: Microsoft has not said. As of 00:55 UTC on 13 November 2026 the incident was still open: the most recent official post found, from the Microsoft 365 Status account on X at 00:06 UTC, described restored servers failing again under traffic, and no later post or all-clear had appeared ^[11]. At its last reading, at 00:30 UTC, Microsoft's public Service Health Status page showed service degradation for Microsoft 365 business and enterprise services, with the user impact described as "Users may be unable to connect to multiple Microsoft 365 services" ^[1]. The page gave no estimated time for full recovery. It only promised the next update by 01:30 UTC on Friday 13 November 2026 ^[1]. The page's headline also listed Microsoft consumer products as degraded, without further detail in its text ^[1].

The most recent official update at the time of checking, posted at 00:06 UTC, was a setback rather than a fix. Microsoft said the servers it had returned to service "can become unresponsive again once they receive traffic" and that it was analysing diagnostic data to find out what triggers this ^[11]. Its status page, last updated at 00:08:53 UTC at the 00:30 UTC reading, added that it was working with networking and platform experts on that analysis ^[1].

In practice, that means three things for anyone waiting:

• Recovery will probably not arrive all at once. Microsoft has said that as capacity is restored, users may experience a gradual recovery as their apps reconnect ^[10].
• Service can come back and drop again. Because restored servers have failed again under load, a working inbox may stop loading for a while before the incident is closed ^[11].
• Only Microsoft's own all-clear counts. The outage is over when Microsoft's status page or the Microsoft 365 Status account says impact is resolved, not when one person's inbox loads ^[1][2].

For the general how-to, such as how to tell whether Outlook is down for everyone, what the status labels mean and how to keep working offline, see Pouyam's earlier guide Outlook Down? How to Check Status and Keep Working.

What happened, hour by hour (UTC)?

All times below are in Coordinated Universal Time (UTC). US Eastern time is five hours behind UTC in November, so 17:54 UTC is 12:54 pm Eastern.

Earlier the same day, a separate Teams incident. Before the email outage, Microsoft handled a Microsoft Teams incident, tracked as TM1550488, that BleepingComputer reports lasted from 9:45 to 10:53 am Eastern (14:45 to 15:53 UTC) and affected users in North and South America ^[12]. Microsoft attributed it to resource contention and said it was fully resolved; it has not said whether it is linked to the later outage ^[12].

17:54 UTC. The Microsoft 365 Status account on X said Microsoft was investigating reports of users having issues accessing Exchange Online mailboxes through multiple connection methods in the Americas, under incident EX1550543 ^[2]. Exchange Online is the Microsoft cloud service that stores work and school mailboxes used by Outlook.

Around 18:00 UTC (about 1 pm Eastern). Downdetector reports of Outlook problems peaked at 138,058, according to Reuters ^[13].

18:07 UTC. Microsoft said the issue may affect Microsoft 365 service connectivity for users in any region ^[3].

18:26 UTC (1:26 pm Eastern). According to BleepingComputer, Microsoft gives this as the start time of the wider Microsoft 365 incident, tracked as advisory MO1550821 ^[12].

18:35 UTC. Microsoft said a portion of its infrastructure was experiencing elevated load across multiple regions, which was likely contributing to the connectivity errors ^[4].

19:31 UTC. Microsoft corrected its first explanation: the elevated load was not driven by more traffic, but by a number of servers being unexpectedly unavailable, which strained the remaining infrastructure ^[5].

20:19 UTC. Microsoft said it had not identified any recent change correlated with the start of impact, but that the failed health checks may originate from a specific component responsible for processing server health ^[6].

21:00 UTC. Microsoft said an alternative service health check method had let a subset of affected servers return to service, and that it was applying this change more broadly ^[7].

21:40 UTC. Microsoft said it was assessing whether reverting a small number of recent configuration updates it had identified could help accelerate recovery ^[8].

22:09 UTC. Microsoft said its actions so far had not provided the anticipated relief and that a core process on affected servers was becoming overwhelmed, causing capacity loss ^[9].

23:04 UTC. Microsoft said a portion of affected servers were back in service and stable so far, that it was shifting traffic to alternate routes and was observing limited recovery ^[10].

00:06 UTC on 13 November. Microsoft said restored servers can become unresponsive again once they receive traffic, that it was temporarily limiting which types of traffic can reach the affected infrastructure in some locations, and that it was rebuilding a subset of servers using a previous configuration to test whether that stops them failing ^[11].

What caused the Outlook outage?

Microsoft has not announced a root cause. It has described how the failure shows up, and its explanation has changed several times during the day, as the timeline above shows. Here is what Microsoft has actually said, in its own terms:

• Not a traffic surge. The load problem came from a number of servers being unexpectedly unavailable, not from an increase in traffic ^[5].
• Failed health checks. Servers were failing automated health checks, and the failures may originate from a specific component responsible for processing server health ^[6]. A health check is an automatic test a system runs on each server; a server that fails it is taken out of service.
• No matching change found, at first. At 20:19 UTC Microsoft said it had not identified any recent change correlated with the start of impact ^[6]. At 21:40 UTC it said it was assessing whether reverting a small number of recent configuration updates could help recovery ^[8]. Microsoft did not say those updates caused the outage.
• An overwhelmed core process. At 22:09 UTC Microsoft said a core process on affected servers was becoming overwhelmed, causing capacity loss ^[9].
• Unknown trigger. At 00:06 UTC Microsoft said it was still analysing what triggers restored servers to become unresponsive again ^[11].

None of these statements names what started the problem. Microsoft has not said the outage was a cyberattack, and it has not said it was not. Claims on social media about hacking, a specific software update or a particular data centre are not supported by any Microsoft statement as of the time of checking.

Why is the fix taking so long?

Microsoft's own updates show a recovery that repeatedly ran into the same wall. The pattern, as described by Microsoft, has been:

1. Restart servers and move traffic. Microsoft paused deployments, moved traffic off the affected infrastructure and restarted affected servers ^[12].
2. Change how health is checked. An alternative health check method brought a subset of servers back, and Microsoft began applying it more broadly ^[7].
3. Admit the early steps were not enough. By 22:09 UTC Microsoft said its actions had not provided the anticipated relief and that it was isolating part of the infrastructure, restarting components and reintroducing traffic to confirm stability before a wider change ^[9].
4. Partial recovery. At 23:04 UTC some servers were back and stable, with limited recovery observed ^[10].
5. Relapse under load. At 00:06 UTC Microsoft said restored servers can become unresponsive again once traffic reaches them ^[11].

The last point explains the slow pace. Bringing a server back is not enough if it falls over as soon as millions of mail apps reconnect to it. Microsoft's latest approach has two parts. First, it is temporarily limiting which types of traffic can reach the affected infrastructure in some locations. Second, it is rebuilding a subset of affected servers using a previous configuration to test whether that stops them becoming unresponsive ^[11].

That approach is careful by design, and it implies a gradual return rather than a single moment when everything comes back. Microsoft has also shifted traffic to alternate routes wherever possible and reported limited recovery ^[10].

How big is the outage, and which services are affected?

Outlook and Exchange Online are at the centre, but not alone. Microsoft's status page lists the potentially affected services as Exchange Online, Microsoft Teams, SharePoint Online, Microsoft 365 Copilot (listed as "Microsoft Copilot 365"), Microsoft Defender XDR, Microsoft Planner, Microsoft To Do, Microsoft Intune, Microsoft Defender for Office 365, several Microsoft Purview services, Power BI exports with sensitivity labels to PDF, parts of the Microsoft 365 Apps admin center, Universal Print, and some Windows 365 Cloud PCs that use Purview Customer Key ^[1].

User reports. Downdetector, which collects reports submitted by users, recorded a peak of 138,058 reports of Outlook problems around 1 pm Eastern, falling to around 34,490 by the evening, according to Reuters ^[13]. Reuters also reported that by 5:47 pm Eastern there were nearly 13,000 reports for Microsoft 365 and 763 for Teams ^[13]. These figures count complaints submitted by users, not the number of people affected.

Knock-on effects. Reuters reported that connectors used by OpenAI's and Anthropic's AI services to reach Microsoft 365 were also hit, and that the electric truck maker Workhorse Group moved its third-quarter results from 12 to 16 November, citing disruption from the outage ^[13].

What Microsoft told reporters. A Microsoft spokesperson said the company was "aware and investigating reports of users experiencing issues with Microsoft 365 services, primarily issues with Exchange Online," according to Reuters and The Verge ^[13][14]. The Verge reported that from just before 1 pm Eastern on Thursday, reports came in from around the world of people unable to access Outlook email through the web or the apps ^[14].

What should you do while Outlook is down?

The fault is in Microsoft's data centres, so nothing on a phone or computer will fix it. The most useful steps are small:

For everyone

• Follow one official source. Microsoft's public Service Health Status page and the Microsoft 365 Status account on X carry the official updates; Microsoft points people to the status page when the admin center is not available ^[1][11].
• Do not rebuild your setup. Microsoft describes a server-side problem with a gradual recovery as clients reconnect ^[10]. Removing and re-adding an account during the outage adds work later without speeding anything up.
• Expect delays, then check. When the service recovers, check the Sent folder and the Outbox to see what actually went out, and resend only what is missing.
• For the full checklist, including working offline, using Outlook on the web versus the apps, reading error codes and avoiding outage-themed phishing, use Outlook Down? How to Check Status and Keep Working. It is not repeated here.

For Microsoft 365 administrators

• Track EX1550543 (Exchange Online) and MO1550821 (wider Microsoft 365) in Service health in the Microsoft 365 admin center, or the public status page if the admin center does not load ^[2][11].
• Tell staff once, with a time for the next update, instead of answering every ticket. Microsoft's own next update was due by 01:30 UTC on 13 November, according to the status page at the 00:30 UTC reading ^[1].
• Expect some users to recover before others, and some to lose access again, because Microsoft is returning servers to service in stages and limiting some traffic types in some locations ^[10][11].

What to watch for next

Three signals will show whether the outage is ending:

• Whether rebuilt servers stay up. Microsoft said it is rebuilding a subset of servers using a previous configuration to test whether that stops them failing ^[11]. A statement that this is being rolled out widely would be the clearest sign of a fix.
• Whether traffic limits are lifted. Microsoft is temporarily limiting which types of traffic can reach the affected infrastructure in some locations ^[11]. Lifting those limits would be a sign that the servers can carry normal load again.
• A clear all-clear and a cause. Until Microsoft says impact is resolved, the incident is open. Until it names a cause, any explanation on social media is speculation ^[6][11].

Every status described above is as of 00:55 UTC on 13 November 2026 (the status page itself was last read at 00:30 UTC). The situation was changing hour by hour, so Microsoft's status page is the place to confirm the current state ^[1].