Microsoft 365 Outage Hits Inboxes at IndiGo, Keka and Equitas Bank

Microsoft 365 went down late on Thursday, November 12, and was still only partly recovered on Friday afternoon, according to reporting from MediaNama and Inc42. Microsoft said servers became "unexpectedly unavailable," and it has promised a post-incident report.

Inc42 dates the start at about 11:30 p.m. IST, which is 6 p.m. UTC, when a core process that sets up secure connections became overwhelmed. Servers then failed automated health checks and dropped out of service, which pushed more load onto the machines still running.

What Microsoft has said

MediaNama reports two incident records. EX1550543 covers Exchange Online mailbox access, first described as affecting users in the Americas "through multiple connection methods." MO1550821 covers Teams, SharePoint Online, Microsoft 365 Copilot, Microsoft Defender XDR, Planner, To Do and Intune. Microsoft later confirmed the problems could reach users in any region.

The company said the extra load did not come from traffic volume, and that it was "not aware of any malicious activity." In a later update it said "a core process on affected servers was becoming overwhelmed," cutting capacity. It also said a component that processes the health checks may have contributed.

MediaNama lists Microsoft's actions: deployments paused, traffic rerouted globally, a configuration change tested on a subset of servers, and temporary traffic limits in specific places. Early recovery did not hold, because servers that came back sometimes stopped responding again.

Incident ID	Scope	Services named
EX1550543	Exchange Online	Mailbox access, multiple connection methods
MO1550821	Other Microsoft 365	Teams, SharePoint Online, Copilot, Defender XDR, Planner, To Do, Intune

India felt it as a lost inbox

Inc42 tracked Downdetector complaints about Outlook from India: about 2,157 at the Thursday night peak, easing overnight, then nearly 4,000 by 10 a.m. on Friday and more than 2,500 by noon. It put the global count at about 140,000 complaints and said services in 74 countries were affected. Both figures are Inc42's and rest on user reports, not Microsoft telemetry.

1. Thursday night peak2157 complaints
2. Friday 10 a.m. IST4000 complaints
3. Friday noon IST2500 complaints

Source: Inc42, accessed 2026-11-13

The Friday figures are rounded in Inc42's wording ("nearly" and "over"), so the bars show the approximate readings.

The business effects were specific. Inc42 lists IndiGo as possibly unable to receive customer emails, Akasa Air with delayed email support, and Keka struggling with offer letters, one-on-one meetings and interview scheduling. Equitas Small Finance Bank asked customers to use its helpline in place of email. Infosys and Cognizant were named in media reports of disruption.

Amit Singh, practice head for managed services at WeP Solutions, said in Inc42's article that "very few have one for the inbox, and the inbox is where contracts, approvals and payments actually move." Ritwik Batabyal, chief technology officer at Mastek, said companies "have reduced application complexity, but inadvertently increased dependency concentration."

Earlier Exchange incidents

Exchange Online had a separate fault days earlier. The Terminal reported that Outlook.com rejected authenticated mail from about November 4 to 10 under incident EX1545193, which Microsoft's record tied to a spam-enforcement rule update. A Microsoft fix for the exploited Outlook spoofing flaw CVE-2026-124194 shipped on November 10. Neither is linked to the current outage in the reporting read for this piece.

Microsoft had given no full-recovery time as of Inc42's Friday afternoon update. The post-incident report on root cause and corrective measures has no published date.