Microsoft 365 outage: Outlook is down. What we know.

Outlook users are reporting that emails won't send.
 By 
Tim Marcin
 on 
an illustrated screen with microsoft outage on it
Credit: Ian Moore/Mashable/Getty Images

Updated on Jan. 22 at 5:31 p.m. ET: Microsoft said it was working toward fixing a 365 outage on Thursday, though noted users may still be experiencing issues.

"We're carefully rebalancing traffic across all affected infrastructure in the region," read a statement on its 365 status page. "We’re proceeding as quickly as possible and this incremental approach will also help us identify whether any additional actions may be required to ensure longstanding recovery."


Microsoft 365 suffered an outage on Thursday, affecting U.S. users going about their workday.


You May Also Like

"Users may be seeing degraded service functionality or be unable to access multiple Microsoft 365 services," the company wrote on its 365 status page.

Microsoft users reported being unable to send or receive email through Outlook, and services such as Teams and Defender may also be affected. Ironically, even the Microsoft 365 status page is having trouble loading for some users.

"Users may be receiving a '451 4.3.2 temporary server issue' error message when attempting to send or receive email through Outlook," read the Microsoft status page.

User-reported issues for Microsoft 365 spiked on Downdetector on Thursday afternoon. The reports appeared to be going down as evening, Eastern time, approached. (Disclosure: Downdetector is owned by Ziff Davis, the same parent company as Mashable.)

Microsoft noted it was working toward restoring services.

"While we've restored the affected infrastructure to a heathy state, further load balancing is required to mitigate persistent impact," read its 365 status page. "We've identified and are implementing additional actions to direct requests and traffic to additional healthy sections of infrastructure to achieve withstanding recovery."

Not being able to send or receive emails is, obviously, a major pain for workers. Lots of folks took to social media to voice their frustrations and, of course, make jokes.

Microsoft has been no stranger to outages lately. It saw two major outages in October alone, with both 365 and Azure crashing that month. There was also the infamous, massive outage in 2024, ultimately caused by an issue with the cybersecurity provider CrowdStrike.

This story is developing and will be updated as necessary...

Topics Microsoft

close-up of man's face
Tim Marcin
Associate Editor, Culture

Tim Marcin is an Associate Editor on the culture team at Mashable, where he mostly digs into the weird parts of the internet. You'll also see some coverage of memes, tech, sports, trends, and the occasional hot take. You can find him on Bluesky (sometimes), Instagram (infrequently), or eating Buffalo wings (as often as possible).

Mashable Potato

Recommended For You
Microsoft 365 Outlook down: Microsoft breaks silence on outage
Microsoft logo

Microsoft 365 outage cause revealed
microsoft 365 logo on phone

Artemis II astronauts need remote help to fix Microsoft Outlook issue in space
Artemis II at launch pad


Verizon outage: Why your phone says SOS, what we know so far
verizon logo on phone

Trending on Mashable
NYT Connections hints today: Clues, answers for April 3, 2026
Connections game on a smartphone

Wordle today: Answer, hints for April 3, 2026
Wordle game on a smartphone

What's new to streaming this week? (April 3, 2026)
A composite of images from film and TV streaming this week.

NYT Connections hints today: Clues, answers for April 2, 2026
Connections game on a smartphone

The biggest stories of the day delivered to your inbox.
These newsletters may contain advertising, deals, or affiliate links. By clicking Subscribe, you confirm you are 16+ and agree to our Terms of Use and Privacy Policy.
Thanks for signing up. See you at your inbox!