Focused Inbox Has Problem Delivering to the Right Place

Problem EX186451 Fixed to Relieve Users Who Can’t Find Email

Yesterday the Exchange Online Focused Inbox had a slight meltdown and delivered all messages to the “Other” part of the Inbox folder. By “Other,” I mean the “Other” view because Outlook clients use two views to present email delivered to the single Inbox folder. Some users were confused, especially those using Outlook mobile, as they didn’t receive notifications for new and potentially important messages arriving into their Inbox.

Microsoft’s problem report says that the issue potentially affected everyone using the Focused Inbox feature. However, it’s not clear how widespread the issue was, but I did hear about it from multiple tenants. The distributed nature of Office 365 and the way that Exchange Online is installed in multiple forests makes it hard for a configuration problem to affect the entire service.

The decision to surface a message in the Focused or Other view is made by a mailbox assistant that processes inbound messages and evaluates them according to criteria built up by the user over time. The default is to put messages into the Other view, but you provide signals over time to instruct the assistant on the messages you think are important (or vice versa). The strongest signal you can give is when you move messages from the Focused to the Other view or back as this tells the assistant to do likewise with other messages. The assistant also looks for clues, like circulars and the like before deciding how to categorize a message. Admins can configure a transport rule to make sure that important email, like messages sent by the CEO for the edification of the whole company, are always placed into the Focused view.

The Outage

I wasn’t impressed at Microsoft’s problem report (Figure 1). Although it is a workaround, instructing users to disable Focused Inbox is liable to cause further confusion once the problem was resolved.

EX186451 problem for the Focused Inbox
Figure 1: EX186451 problem for the Focused Inbox

I guess the other question raised by the problem is (once again) how does Microsoft test changes before deployment into the production environment. The answer, in this case, is “poorly.” Software can fail, but configuration changes should be validated before they go anywhere near production.


Focused Inbox is covered in the Companion Volume of Office 365 for IT Pros. It’s a good example of a topic that is not of tremendous interest to most Office 365 admins until something bad happens…

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