Microsoft Office 365 Outage Reported For Some Users

Microsoft reported that some users have been unable to access Office 365 mailboxes since early Thursday morning, Eastern time.

The Microsoft 365 Twitter account disclosed the outage just before 5 a.m., Eastern time. The account tweeted again just before 9 a.m. Eastern time, saying that "we've determined that a subset of Domain Controller infrastructure is unresponsive, resulting in user connection time outs."

"We're applying steps to mitigate the issue," the account tweeted.

In a statement provided to CRN, Microsoft said: "We’re working to resolve difficulties a limited subset of enterprise customers in Europe are experiencing when attempting to access Exchange Online.”

[Related: The 10 Biggest Cloud Outages Of 2018]

We’ve determined that a subset of Domain Controller infrastructure is unresponsive, resulting in user connection time outs. We’re applying steps to mitigate the issue. More details can be found in the admin center published under EX172491.

— Microsoft 365 Status (@MSFT365Status) January 24, 2019

Reports of the outage on DownDectector.com began early in the morning, Eastern time, on Thursday, and reports on the site have continued steadily in the following hours.

Initially on Thursday morning, the Microsoft 365 Status Twitter account posted that Microsoft was "investigating an issue where users can't access their mailboxes through multiple protocols."

"Any time there is a major outage of a system as ubiquitous as Office 365 I am reminded of the often-overlooked need to make cloud-to-cloud backups of vital systems such as email and cloud storage," said Robby Hill, CEO of HillSouth, a Microsoft partner based in Florence, S.C., in a previous email to CRN.

The incident follows November's outage of Azure and Office 365 services. That outage affected users who were required to sign in using multifactor authentication.