What caused Outlook outage? Microsoft reacts amid email failures, authentication issues

Microsoft is investigating a major service disruption affecting Exchange Online users, causing email delays and authentication errors.

Microsoft stated the problem was linked to the cloud-based service, Microsoft Exchange Online.

Multiple Dropbox users have been emailed by the cloud storage company to advise them that a security breach saw unauthorised access to their account. The root cause appears to be a lack of authentication by Dropbox when attackers created a single sign-on option through a third-party company … more…

Microsoft posted an update on Exchange Online, which has been down for much of Monday.

Microsoft says it's testing a fix for the widespread Outlook issues that have led to email delays and failures.