Microsoft's business email service was still degraded today, more than 11 hours after problems surfaced on Thursday afternoon US time. The company's public Service Health Status page, last updated at 5:46:34 AM UTC on Friday, November 13, 2026, lists 19 Microsoft 365 services affected through their dependence on Exchange Online, says engineers are still trying to pinpoint the cause, and promises a Post-Incident Report once the problem is mitigated.

In Short

Exchange Online, the mail system behind Outlook for Microsoft 365 business customers, was still degraded today, and the disruption reaches into 18 other Microsoft 365 services that rely on it, from Teams calendars to Copilot and Microsoft's own security tools. Companies that run mail, meetings and compliance on Microsoft 365 may be unable to open mailboxes, may see mail arrive late, and may find that links in protected emails fail to open. Microsoft says it is not aware of malicious activity, but it has not identified the underlying cause, and its reference to a "traffic influx" sits awkwardly beside earlier statements, reported by several outlets, that the problem was not driven by more traffic. A full account is promised only after mitigation, and Microsoft set its next update for 7:00 AM UTC today.

What the status page says

The headline banner on the page reads: "Service degradation on Microsoft 365 (Business or Enterprise) and Microsoft consumer products." Under the business heading, Microsoft summarises the problem in a single line: "Users may be unable to connect to multiple Microsoft 365 services."

The explanation that follows is the key to the breadth of the incident. According to Microsoft, "Features of the Microsoft 365 services below that interact with Exchange Online and email services are impacted. Elements of those services that do not depend on interaction with Exchange Online remain functional." The outage, in other words, is not 19 separate failures. It is one failure in the mail and calendar layer, felt wherever another product reaches into that layer for data.

For Exchange Online itself, the entry is specific about the connection methods affected: "Users may be unable to access their mailbox using Outlook on the web, Outlook desktop (MAPI), Exchange ActiveSync (EAS), or REST-based connections, and email delivery may be delayed." Those four routes cover the browser version of Outlook, the desktop Outlook client, the protocol most phones use to sync corporate mail, and the programmatic interfaces that third-party software uses to read mailboxes. Between them, they account for nearly every way a business user or an integrated application reaches a mailbox.

The scope statement is more cautious. "This issue may affect users attempting to access the affected Microsoft 365 services," the page says. Microsoft does not give a count of affected tenants, users or regions, and it does not say that every customer is affected.

There is also a note on why this information sits on a public page at all: "Information about this issue is posted on this page because Microsoft 365 administrators may be unable to access the admin center to get Service health information." The admin center is where Microsoft normally posts incident details for IT teams. When that is unreliable, the public page becomes the fallback, which is itself an indication of how far the problem reaches into Microsoft's own management tools.

Nineteen services, one dependency

The list of affected services runs from Exchange Online through to Windows 365, the Cloud PC product. Taken together, the entries show how much of the Microsoft 365 suite treats the mailbox and calendar as shared infrastructure.

Productivity and collaboration

Microsoft Teams remains largely usable for live communication. "Most of the core functionality including joining calls, meetings, group chats, and channel messages are not impacted," according to the page. The failures sit wherever Teams depends on Exchange: calendar scheduling, invites, viewing and meeting edits. Microsoft states plainly that "Creation of Live or Virtual events fail." Navigating to app chats, adding new contacts and syncing contacts in settings also fail, and users may be unable to create or delete private or shared channels, although standard channels work.

SharePoint Online is partly insulated. Features that depend on Exchange Online may be impacted, but "Accessing files stored directly in SharePoint Online remains functional." The Microsoft 365 apps entry adds that users may be unable to view their recently used files, a list that draws on activity data rather than the files themselves.

Microsoft Planner users "are experiencing Plan and Task operation reliability issues," and Microsoft To Do "may not load." Microsoft 365 Education lists Assignments, Reading Progress and Speaker Progress among the features that may be impacted. Universal Print users may hit errors submitting print jobs or using admin features.

Copilot

The entry for what the page calls Microsoft Copilot 365 describes a double failure. According to Microsoft, "Users may be unable to load Copilot Chat or receive responses in the web and desktop apps, and Copilot experiences may be unable to access work data such as email, calendar, and files." The Teams entry adds failures with Copilot responses for Outlook, calendar or Microsoft 365 files.

That matters because Microsoft has positioned Copilot since 2023 as the layer that sits on top of a company's mail, meetings and documents. When the mail layer goes, so does much of the assistant's context. Microsoft said in July that Microsoft 365 Copilot surpassed 30 million paid seats, and in October it reported that Copilot daily users were up nearly 50 percent quarter over quarter. Each of those seats leans on Exchange Online for a large share of the work data it reads.

Security and compliance

Some of the most consequential entries sit in Microsoft's security stack. For Microsoft Defender for Office 365, the page lists failures for "scenarios including access to Safe Links, Safe Attachments, protection and submission policies, and attempts to view Quarantine, Threat Explorer, and Email remediation events." Delays may also affect Tenant Allow/Block list changes, unified role-based access control, reporting, message traces, content extraction and outbound protection.

The Safe Links line has a direct effect on anyone receiving mail at an organisation that uses the feature. Safe Links rewrites URLs in incoming messages so they can be checked for phishing at the moment of the click. According to Microsoft, "Users clicking on wrapped/rewritten URLs typically processed by Safe Links will result in a failure to navigate, as Safe Links fails to process it." A link in an email that has already been rewritten, whether in a supplier invoice, a client brief or a newsletter, simply does not open. The page adds that users who manage to reach the Quarantine portal "may encounter failures when attempting to release items from quarantine," so legitimate messages held for review may stay held.

Microsoft Defender XDR users may be unable to load Microsoft Defender portal pages or solution tabs. Microsoft Purview, the compliance suite, lists the longest entry on the page: authorization, auto-labeling, data loss prevention across Microsoft 365 services, Communication Compliance, Information Protection label and auto-labeling policies, role-based access control and Data Classification are all described as impacted. Audit searches, protected content creation, eDiscovery search and export, and On Demand Scan may also be affected, and users may be unable to open protected content at all.

Data, APIs and reporting

Microsoft Graph, the programming interface through which many third-party applications reach Microsoft 365 data, is affected wherever requests touch Exchange. According to Microsoft, "API requests that access Exchange Online data, such as mail, calendar, and contacts, may time out," which can prevent users from managing Teams, channels, membership and apps, or sending activity notifications through the Graph API. Any external tool that reads a calendar or mailbox through Graph inherits the problem.

On the analytics side, Microsoft Fabric users may see failures when exporting reports with sensitivity labels to PDF or PowerPoint, when updating labelled artifacts, or when opening a labelled pbix file in Power BI Desktop. Microsoft offers a workaround on the page: users "can remove the sensitivity label from the affected item to complete the operation, if their organization's data protection policies allow it." Power BI has a narrower entry: "All users may intermittently be unable to export reports with MIP sensitivity labels to PDF in Power BI."

Administration and devices

The Microsoft 365 admin center entry says admins may be unable to load some pages, and the Microsoft 365 Apps Admin Center lists Cloud Update, Cloud Policy and Inventory as affected. For Microsoft Intune, the mobile device management service, Microsoft writes in the past tense: device enrollment, device check-in and device compliance policies "may have been intermittently impacted." The wording suggests those scenarios were hit earlier rather than failing at the time of the update.

Windows 365 has the most conditional entry. Only customers who configured their tenant and Cloud PCs to use Microsoft Purview Customer Key, a feature that lets an organisation supply its own encryption keys, "may have users who are unable to connect to their Cloud PCs."

What Microsoft says about the cause

The current status section is the only part of the page that addresses the cause. It reads: "We're continuing to pursue multiple workstreams to pinpoint the underlying cause of the traffic influx and advance the recoverability of the backend servers. We're taking a measured approach to identify and repair affected infrastructure to improve the ability to confirm the developed changes were applied. We're tracking the results of this approach to verify the servers are showing the anticipated recovery and performance intended."

Three points stand out. First, Microsoft has not yet found the root cause; it is still running "multiple workstreams" to find it. Second, the problem involves both a traffic influx and backend servers that need help recovering. Third, the "measured approach" language suggests Microsoft is repairing infrastructure in stages and checking each step, rather than applying a single fix across its fleet at once.

On security, the page is direct: "As of now, we are not aware of any malicious activity that is causing this incident." Microsoft adds that it "will continue to treat this incident with urgency and priority until full resolution," and commits to a fuller account afterwards: "Once mitigated, we will provide full details of the root cause, defense-in-depth repair items, and more within a Post-Incident Report."

The next update was promised by 7:00 AM UTC today. The page gives no estimated time to full recovery.

A discrepancy over traffic

The phrase "traffic influx" is harder to square with what Microsoft said earlier in the incident. According to ABC News in Australia and Windows Latest, Microsoft stated on Thursday that the disruption was not driven by an increase in traffic, and attributed it instead to a number of servers becoming unexpectedly unavailable. ABC News in the US reported that Microsoft described some infrastructure as experiencing elevated load across multiple regions as a result of those servers dropping out.

Later updates, as reported by ABC News in the US and ABC News in Australia, said that servers Microsoft returned to service could become unresponsive again once they began receiving traffic. ABC7 in San Francisco reported that Microsoft attributed this to a process on the affected servers that is responsible for establishing secure connections becoming overwhelmed. Read together, the statements point to a pattern in which recovering servers are swamped as connections pile back onto them. The status page does not spell out where the influx comes from, however, and the Post-Incident Report is the document that would settle it.

When it started

Microsoft's public page carries no start time and no incident identifier. Other reports fill part of that gap. According to Windows Latest, Microsoft's admin center advisory, reference MO1550821, put the start of the problems at around 1:25 PM Eastern Time on Thursday, November 12, which is 6:25 PM UTC. Windows Latest also said it had reason to believe limited problems began earlier in the day. Cyber Security News and Windows Latest both reported a second reference, EX1550543, for the Exchange Online mailbox issue.

ABC News in the US reported that Microsoft first described the issue as affecting access to Exchange Online mailboxes through multiple connection methods in the Americas, before widening it to users in any region. Outage reports climbed quickly: ABC News in Australia said more than 120,000 users reported Outlook problems on Downdetector's US site at the peak, with more than 45,000 reporting problems with Microsoft 365. Downdetector counts user reports, not confirmed outages, and the figures are not comparable with Microsoft's own impact data, which the company has not published.

ABC News in the US reported that Microsoft paused deployments, moved traffic away from affected infrastructure and restarted servers on Thursday, and that around 6 PM Eastern Time it began returning a portion of the affected servers to service. By Microsoft's 5:46 AM UTC update today, 11 hours and 21 minutes had passed since the 1:25 PM Eastern start time cited by Windows Latest, PPC Land calculates, and the page still described the service as degraded.

ABC News in Australia also reported that OpenAI and Anthropic said their Microsoft connectors, which let their AI assistants read Microsoft 365 data, were affected.

What is not affected

The page draws some clear lines. Under the Microsoft Azure heading, it reads: "No Azure issues detected at this time." The Power Platform Admin Center section carries no incident, only a standing note that the page is updated when tenant administrators cannot reach that admin center.

The Microsoft consumer products section, which covers "Microsoft products and services designed for personal use by families, individuals, and students," is marked with the same "Service degradation" label as the business section. The page's summary view does not name which consumer products are affected.

Within the business suite, Microsoft repeats that elements not dependent on Exchange Online "remain functional." Files stored directly in SharePoint Online, Teams calls and meetings, group chats and standard channel messages are among the features Microsoft says still work.

Service credits

For businesses, the financial question is whether the outage triggers Microsoft's service level agreement. According to Windows Latest, which cites the April 2026 version of Microsoft's volume licensing terms, Exchange Online carries a monthly uptime commitment of 99.9%, with a 25% service credit if availability falls below that level, 50% below 99% and 100% below 95%. Uptime is measured in user-minutes, and credits must be requested through the Microsoft 365 admin center within one month after the end of the affected billing month, the outlet said. Windows Latest added that users of personal accounts are unlikely to be eligible.

The thresholds translate into tight windows. In a 30-day month, 99.9% availability allows about 43 minutes of downtime, 99% allows 7.2 hours and 95% allows 36 hours, PPC Land calculates. A user unable to reach a mailbox for the full 11 hours and 21 minutes up to this morning's update would account for about 1.6% of the month on their own. Because the measure is calculated across users and depends on how many in a tenant were actually affected, no single tenant's position can be read from the status page.

Why this matters for the marketing community

For agencies, publishers and advertisers, Outlook and Teams are the plumbing for client communication, approvals and reporting. Several entries on Microsoft's list map directly onto that work. Delayed mail delivery affects campaign briefs, invoices and newsletter sends to business inboxes. The Safe Links failure means that links in emails received by organisations using Defender for Office 365 may not open, which touches every sender whose messages land in a protected Microsoft 365 inbox, including B2B marketers measuring clicks. The Teams entry on Live and Virtual events affects anyone setting up webinars on the platform during the outage, and the Graph timeouts reach any tool that syncs calendars or contacts through Microsoft's interfaces.

The incident also adds to a run of infrastructure failures PPC Land has tracked. In July 2024, a faulty CrowdStrike Falcon Sensor update took Windows workstations offline across banks, airlines, broadcasters and the NHS. In October 2025, a DNS resolution failure for DynamoDB endpoints in Amazon Web Services' US-EAST-1 region disrupted 142 AWS services for more than 15 hours, taking down Snapchat, Fortnite and several UK banks. Marketing platforms are not immune either: in July 2025, Google Analytics suffered a platform-wide outage, and in December 2024, creators were left without reach when Meta's apps went down.

What links these events is concentration. A small number of hyperscaler providers and software vendors now carry a large share of business infrastructure, so a fault in one layer travels quickly. Microsoft's status page illustrates the point within a single vendor: one degraded mail service, 18 dependent products affected.

There is a compliance dimension too. Purview's data loss prevention and labelling controls are listed as impacted. PPC Land reported in September that 47% of managed service provider professionals surveyed by Augmentt said they had seen an AI or Copilot related data exposure, or near miss, inside a client's Microsoft 365 tenant in the previous 12 months. The status page shows those controls can fail alongside the mail service they are meant to govern. Microsoft's Fabric workaround, which involves removing sensitivity labels where an organisation's policies allow it, shows the trade-off some customers face between completing a task and keeping protection in place.

The scale of Microsoft's commercial business explains why the incident reaches so many organisations. Microsoft reported in October that Microsoft 365 commercial cloud revenue reached $27.78 billion in its September quarter, up 17%, with paid commercial seats up 5%. The same results showed capital expenditure of $45.2 billion for the quarter, with calendar-2026 spending expected at approximately $170 billion. Some of that capacity is meant to make services like Exchange Online more resilient. The Post-Incident Report should show what failed in this case and which "defense-in-depth repair items" Microsoft plans to make.

Timeline

Summary

Who: Microsoft, and the business and enterprise customers of Microsoft 365 who rely on Exchange Online for mail and calendars, along with 18 other Microsoft 365 services that depend on it, including Teams, Copilot, Defender, Purview, Graph, Intune and Windows 365.

What: A service degradation in which users may be unable to reach mailboxes through Outlook on the web, Outlook desktop, Exchange ActiveSync or REST-based connections, mail delivery may be delayed, and Exchange-dependent features in 18 other services fail or slow down. Microsoft says it is pursuing the cause of a "traffic influx" and the recovery of backend servers, and is not aware of malicious activity.

When: Problems began on Thursday, November 12, 2026, at around 1:25 PM ET according to Microsoft's advisory as reported by Windows Latest. Microsoft's status page was last updated at 5:46:34 AM UTC today, Friday, November 13, with the next update promised by 7:00 AM UTC.

Where: Microsoft 365 business and enterprise services. Microsoft first described the issue as affecting the Americas before saying it could affect users in any region, according to ABC News. The status page reports no Azure issues and marks Microsoft consumer products as degraded without naming them in its summary view.

Why: Microsoft has not yet identified the underlying cause. The status page refers to a traffic influx and backend servers that need recovery, while earlier statements reported by several outlets said the problem stemmed from servers becoming unexpectedly unavailable rather than from increased traffic. Microsoft has committed to publishing a Post-Incident Report with the root cause and repair items once the incident is mitigated.