Microsoft Exchange Online in North America experienced a mysterious intermittent and inconsistent disruption of its Exchange Online yesterday that follows on a disruption Monday to Microsoft's Lync Online.
Reports of troubles with the Exchange service started cropping up early Tuesday morning Eastern Time with varying symptoms.
Microsoft says it suffered two problems that affected most of its hosted Exchange services. At 4:45 p.m. it reported to customers that mail that had been stuck in queue was freed up and that flow was improving but it might take several hours for all the delayed messages to be delivered. Connectivity issues might continue for several more hours, but Microsoft had identified potential causes for that problem.
Some users reported that they were not receiving emails, some said when they sent mail it sat in their Outboxes, some said when they tried to send they got notices that the client couldn't connect to the cloud service.
The impact of the Exchange problems varied desktop-to-desktop within the same corporate networks using the service. For example, one user at a mid-size enterprise had no email service for more than six hours. Two others at adjacent desktops intermittently received batches of emails followed by hours of receiving none followed by more batches. When email did arrive, some had been sent recently, some hours before.
Microsoft told corporate customers that started investigating the problems at 9:17 a.m. Eastern and described them as being unable to access Exchange Online services. The company told customers that some might be able to access the service via browser.
The company updated its customers at 2:55 p.m. Eastern saying that engineers had identified a potential cause for the disruption, but didn't specify what that was.
A spokesperson for Microsoft said the company was looking into the reports but had no statement about the cause, extent and status of the problem.
Separately, Microsoft acknowledged yesterday's Lync problems but offered little detail. "[S]ome users in North America experienced issues with Lync Online due to network routing infrastructure issues," was what a spokesperson had to say in an email in response to a request for details about what happened.