Outlook has been hit by a nationwide outage, leaving Americans unable to send or receive emails in the middle of a work day.
Users reported issues with the website and app, which is used by millions of office workers.
The glitches hit around 9:00 am ET, plaguing users from New York City, to Chicago and Los Angeles.
The Outlook outage comes as Microsoft has been down for users Monday morning, impacting Microsoft 365 and Microsoft Teams.
Outlook has been hit by a nationwide outage, leaving Americans unable to send or receive emails in the middle of a work day
Downdetector, a site the monitors online outages, shows more than 8,000 users in the US were having problems by 12:40pm ET.
Approximately 69 percent of reported problems cite Outlook's website, 20 percent for the app and 10 percent of users are unable to login.
More than 1.2 million Americans use Outlook.
Users flocked to X to share their frustrations about the outage, with one posting: 'So Microsoft outlook decides to go down this week? Sounds like Microsoft wants us to take an early Thanksgiving break.'
Microsoft's Support account replied at 1:00pm ET: 'Our specialists are currently addressing an issue impacting users attempting to access Exchange Online or other Microsoft 365 services, and they’re working to get this difficulty sorted.'
UK Outlook users reported issues earlier this morning, but it seems the glitches have just hit Americans recently in the day.
On X, Microsoft shared an update saying: 'While we continue to work on mitigating the issue, we’ve added a comprehensive list of impacted services and scenarios to the more info section.'
An X user shared: 'My outlook being down is mercury retrograde coded.'
And another posted: 'Outlook is down as a signal from the universe that we shouldn't be working this week.'
Users flocked to X to share their frustrations about the outage
This latest outage comes just four months after Microsoft suffered an outage described as the 'most serious IT outage the world has ever seen.'
The outage hit supermarkets, banks, telecoms, streaming services and PCs, with airports, railways and GP surgeries also among those reporting problems.
It later emerged that the issues had been caused by a glitch in the Crowdstrike cybersecurity service which is used by Microsoft.
The Microsoft outage was triggered by a bug in Crowdstrike's software update, which was deployed to its 'Falcon Sensor,' which searches for viruses and malicious attacks.
The resulting disruption left millions of passengers stranded at airports as major airlines grounded planes.