Office 365 bug: Exchange Online, Outlook emails sent to junk folder

Microsoft is investigating an Office 365 issue causing Outlook and Exchange Online emails to skip recipients' inboxes and being sent their junk folders instead.

"We're investigating an issue in which email is being sent to the junk folder," Microsoft shared on the company's Microsoft 365 Status Twitter account.

"We're investigating a potential issue and checking for impact to your organization," Microsoft added in the admin center.

The company added that more information will be shared within 30 minutes under EX258373 in the Microsoft 365 admin center.

The Microsoft 365 Service health status page is currently directing customers to the Microsoft 365 Status Twitter account for more details regarding this ongoing incident.

We're investigating an issue in which email is being sent to the junk folder. We'll be providing updates under EX258373 in the admin center.

Microsoft fixed another issue today caused by a recently deployed spam rule that prevented users from forwarding email messages using Exchange Online.

Earlier this month, another Office 365 issue resulted in legitimate emails sent from multiple domains (including Google and LinkedIn) getting tagged as malicious and quarantined.

Last month, a Microsoft 365 outage prevented Exchange Online users from sending and receiving emails, with messages being stuck in transit and not reaching the recipients' inboxes.

Exchange Online was also knocked down by a widespread authentication outage in March, preventing users from logging into their accounts due to an Azure Active Directory (Azure AD) configuration issue.

The March massive outage affected multiple other Microsoft services at the time besides Exchange Online, including Microsoft Teams, Forms, Xbox Live, Intune, Outlook.com, Office Web, SharePoint Online, OneDrive for Business, Yammer, and more.

In September, Microsoft users experienced another worldwide outage showing "transient" errors that knocked down Office 365 and several other related services, including Microsoft Teams, Office.com, Power Platform, and Dynamics365.

This is a developing story ...