Microsoft 365 Outage Grounds Email — and Some CEOs Never Relied on It

A widespread Microsoft 365 outage on Thursday cut off Outlook, Teams and Copilot for thousands of users worldwide, and the disruptions — which Microsoft attributed to overloaded infrastructure and unresponsive servers — continued into Friday before full recovery. For HR and internal-communications leaders, the outage is a live stress test of how much people-process infrastructure still depends on a single vendor's email stack.

The timing matters. Workplaces and government operations around the world reported disruption Thursday, according to Business Insider. Microsoft executive Charles Lamanna addressed the failures in a post on X: "We regret that today's outages caused disruptions for our customers, and we are working to address the issue." He added: "We will continue to share more information as soon as we have it, and for now I can confirm that there is no indication this is the result of malicious or cyber activity." Microsoft did not immediately respond to a request for comment.

How did workers react?

The human response split along familiar lines. Some employees celebrated on social media, joking that their bosses should give them Friday off because they could not possibly work without Teams and email. Others posted angrily, pressing Microsoft to fix the problem fast so they could get back to their jobs.

For people-operations teams, that split carries a real question: which channels are essential, and which simply feel essential because habit made them so? The outage turned a routine dependency into a visible operational risk, and several prominent executives have already answered the question by leaving email behind almost entirely.

Which leaders barely use email?

A handful of well-known CEOs and founders have told Business Insider in past interviews that they rarely touch email — a posture that suddenly looks less eccentric and more like continuity planning.

• Kevin O'Leary. The "Shark Tank" investor said in a December interview that he gave up email after drowning in messages. "I don't do emails anymore because I get anywhere from 2,000 to 4,000 a day," O'Leary said. He tried various filtering systems but could not stop the flood. People who need him now reach him through messaging apps.
• Brian Chesky. The Airbnb CEO told Time in September: "I don't know if I write an email a week." He still responds to emails daily but almost never initiates them, favoring texts, calls and in-person conversations. "I just find it inferior to almost every other form of communication," Chesky said, arguing that texts feel more personal and arrive faster.
• John Paul DeJoria. The 82-year-old billionaire cofounder of John Paul Mitchell Systems and Patrón Tequila goes furthest of all. "I don't even own a computer," he told Business Insider in June. He has no email address, borrows his assistant's computer when necessary, and prefers calls or handwritten letters.
• Wolfgang Puck. The celebrity chef manages his restaurant empire by voice rather than inbox. "I don't enjoy emails very much. I like talking to people directly. I think you understand people better that way," Puck told Business Insider earlier this year.
• Melanie Perkins. The Canva CEO takes a different cut: email in its place, not in her pocket. "I don't have email or Slack on my phone," Perkins said on a podcast last year. "When I shut my laptop, I actually tune out." She stays reachable for emergencies by call or page but otherwise separates work from downtime.

What should HR teams take from it?

The executive patterns cluster into three distinct strategies, and each maps onto a workplace policy choice. O'Leary and DeJoria replace email with other channels entirely, shifting contact onto assistants and messaging platforms. Chesky and Puck treat email as read-only, keeping responsiveness while moving real decisions to calls and face-to-face talk. Perkins keeps email but fences it off, a boundary that doubles as a wellbeing practice rather than a productivity hack.

None of these leaders is typical, and their volume of inbound mail far exceeds most employees'. Still, the numbers make the case that inbox load at the top has already broken the tool: somewhere between 2,000 and 4,000 messages a day, by O'Leary's own count, email stopped functioning as communication and became ambient noise.

The outage also sharpens a channel-resilience question that sits squarely with HR and IT jointly. If a single vendor failure can silence Outlook, Teams and Copilot at once, organizations may want redundancy in how they reach employees — especially for time-sensitive items like payroll alerts, safety notices or benefits deadlines. The employees joking about a Friday off were harmless. The ones who could not work at all were not.

Microsoft has said it is working to address the issue and promised further updates, while confirming no evidence of malicious activity. As multi-day outages of core workplace tools recur, HR leaders may find the bigger lesson is less about Microsoft's servers and more about whether their own communication habits, and those of their executives, have a single point of failure.